Mailgun release notes

AI Insights is now live in Mailgun Optimize, out of beta. Click through any of the past seven days to see what happened, whether it was a good day or a bad one, and what to do next. And you don't have to live in the dashboard to stay on top of it. Set up alerts to hear about issues where you already work. 

Why should I care? 

You have your delivery data. But you lack interpretation. Delivery rates, bounces, and failure counts tell you something changed, but not why. AI Insights reads your Mailgun delivery and reputation data and tells you what’s going on and what to do, in plain language.  

1. Your past week, one day at a time. Click into any of the last seven days to see what happened. Days with issues are flagged with a red dot, so you know where to look first. 

2. Know what to do next. Each day comes with a plain-language summary, not a chart to decode. Days with delivery issues include the most likely causes and recommended actions. 

3. Good days and bad days, at a glance. Issues show in red. When a day goes well, AI Insights shows what’s working in green, so you can keep it up. 

4. Get alerted where you already work. No need to keep checking the dashboard. Set up email, Slack, or webhook alerts, and AI Insights lets you know when it detects an issue. 

5. See reputation risks, not just delivery stats. A new Reputation card calls out deliverability issues, like spam trap hits on a sending domain or an IP on a blocklist. Each one comes with a recommended fix, like verifying your email addresses with Mailgun Validate or requesting delisting. 

What you need to do 

Already on Optimize? Find AI Insights in your Optimize nav and turn it on. 

Want alerts? Turn on AI Insights alerts using the bell icon top right, then choose email, Slack, or webhook.  

New to Mailgun entirely? Compare plans and start a trial at mailgun.com/pricing/optimize. 

Already sending with Mailgun, but new to Optimize? AI Insights is part of every Optimize plan, and your first month is free on Pilot and Starter. Start a 30-day free trial. 

Each team keeps an eye on different data. Marketing wants to know open and click rates, Deliverability wants to know what critical failures are happening, etc. That’s why we’ve released a user configurable dashboard so the data that matters to you is front and center every time you log in. 

Why should I care? 

It’s the same dashboard you know, now built around you and your needs. 

• Your dashboard. Your rules. Pick the metrics that matter to you from the widget library. Show each one as a stat card, bar chart, or line graph. Add it, move it, resize it, make it yours. 

• Your go-to reports, right where you land. Create a Metrics report by domain and time frame, then pin it. It stays exactly how you set it. 

• Everything in one place. Right when you log in. Delivery rate, bounce rate, and failed rate, side by side. 

• Spot changes at a glance. A bounce spike is the first thing you see, front and center. 

• Built for you, not the whole account. Every user saves their own view. Your teammates keep theirs. 

Log in. See what matters. Get back to work. 

What you need to do 

Nothing to turn on. Open your dashboard, click customize and add your first widget. A quick in-app welcome guide walks you through it. You can also visit our help center article at any time.  

Note: this customizable view is available for paid Mailgun Send plans. Free users will see a revamped dashboard with a default chart layout. Mailgun Optimize views are coming soon. 

Blocklist Monitoring in Mailgun Optimize now checks your email addresses, not just your domains and IPs. That means any address in your email, like the From, Reply-To, or unsubscribe address. Spamhaus HBL monitoring checks your addresses against the Spamhaus Hash Blocklist (HBL). It lives in the new Content tab and builds on the domain monitoring you already have. 

It’s live now for all Optimize accounts with domain monitoring enabled. 

Why should I care? 

Your domain looks healthy. Your IPs are clean. Yet mail carrying one address keeps getting filtered. 

Optimize has always watched your domains and IPs. Now it also checks the Spamhaus HBL, which flags individual addresses, so you know exactly which one to fix. 

1. Catch flagged addresses, not just flagged domains. See exactly which of your addresses Spamhaus has listed, so you fix the right thing first. 

2. Build on what you already monitor. Add up to 10 addresses to any domain you already monitor. No separate monitoring setup. 

3. Decide where these alerts go. HBL alerts have their own setup, so you choose where they land: email, webhook, or Slack. 

4. Spot your riskiest addresses fast. The Content tab shows how many addresses have threat detections and which ones are hit most. 

5. Trace what happened, and when. Click any address to see its last 30 days of monitoring history, updated live as detections come in, with the threat type for each one. 

What you need to do 

Go to Optimize > Blocklist Monitoring > Content. Select Manage monitoring or Get started, pick a monitored domain, and add the addresses you want to watch. You can also open any monitored domain and manage its addresses there. The domain must already be monitored. Then set up HBL alerts to choose where detections are sent. 

Your existing domain and IP monitoring doesn’t change. If you stop monitoring a domain, its address monitors are removed automatically. 

Keep the feedback on the email. Mailgun Inspect now lets teams comment on a test, flag emails with issues, and tag the teammate who owns the fix. It all happens in the Inspect web app, right where the renders are. 

Why should I care? 

Email QA feedback lives everywhere. Screenshots in Slack, notes in a doc, "which client was that again?" in a meeting. Approvals stall and issues slip through. This is for teams with more than one person touching a send before it goes out. 

• Review as a team, not a screenshot chain. Comments and flags live on the preview itself, so context never gets lost in a separate thread. 

• See only what needs you. Filter to flagged emails so reviewers spend time on what needs attention, not the whole batch. 

• Route it to the right person. Tag a teammate to assign the fix. They get an email notification, so nothing waits on a forwarded screenshot. 

• Flag it, fix it, retest it. Pair flags with the HTML email editor and close the loop in one place. 

• Bring the whole team. Inspect includes unlimited seats, so everyone who needs to weigh in can, with no per-user cost. 

What you need to do 

Open any new test in the Inspect web app to start. Sending tests to an Inspect email address? Generate a new one to use the new features. 

Collaboration lives in the Inspect web app. It isn’t part of the Chrome or VS Code extensions. 

Light & Dark Mode Dual View shows the light mode and dark mode previews of the same email, on the same client, side by side in Mailgun Inspect. Click Compare on any preview that has a light and dark pair. 

Why should I care? 

Dark mode can hide a logo or turn text low contrast. If your subscribers read in dark mode, that costs you clicks. Now you can spot it in seconds. 

• See light and dark mode at once. View both previews of the same email, on the same client, side by side. 

• Flip in one click. Toggle between light and dark mode for a single preview without hunting for a second result. 

• Previews grouped as pairs. Inspect now shows the light and dark mode previews of each client together. 

• On every Inspect plan. Basic, Premium, and contract plans all include Light & Dark Mode Dual View. 

What you need to do 

When you set up a test, select both the light and dark mode version of a client. Then click Compare on that preview. Preview usage works the same as before: each light or dark mode rendering counts as one preview. 

Not using Mailgun Inspect yet? Start a 30-day free trial. 

One QA fix shouldn’t take five tabs. Mailgun Inspect now has an HTML email editor in the Fix issues tab. All you need to do is click the HTML preview and you'll be able to edit the text directly. You can save your fix as a new version and rerun your previews and code checks, if you'd like.

Why should I care? 

Until now, every fix happened somewhere else. Find the issue, export the HTML, edit it in another tool, re-upload, and rerun the test. After a few rounds, it’s hard to know which version you actually tested. This is the most requested Inspect feature to date. 

• Fix it where Inspect finds it. No export. No re-upload. 

• See an accessibility issue. Fix it on the spot. When Inspect catches any accessibility, image, or link issues, you can now click on one, which highlights the issue in the code. Then you can fix it right there in the code.

• Every fix saved. Every version restorable. Save each edit as its own version with a note on what changed. Restore any version and copy out the exact one you mean to ship. 

• Retest on the same clients, automatically. Save a new version and Inspect reruns previews and code checks. Catch a regression before it reaches an inbox, not after. 

What you need to do 

On Premium or a contract plan of Mailgun Inspect already? Get started with our step-by-step guide. Not yet a Mailgun Inspect user? Try the Premium plan free for 30 days.

Many customers use Mailgun Routes to bring inbound email into systems built around JSON, from support platforms to custom applications. Until now, every Route notification was delivered as form-encoded data, so teams whose endpoints were built for JSON needed to introduce an extra translation step, such as a middleware service, before that data could reach their system. Mailgun Routes now support JSON payloads natively. Add json to the end of a route’s destination URL, and Mailgun delivers the parsed message directly as application/json, ready for your endpoint to use as it arrives. 

Why should you care? 

Native JSON delivery gives your team more flexibility in how Routes fit into your existing systems, while every current integration continues to operate exactly as it does today. 

• Send Route notifications directly into JSON-based systems. When your destination URL ends in json, Mailgun delivers the parsed message as application/json, in the format your endpoint expects. 

• Adopt the new format on your own timeline. JSON delivery is configured per route, so you can move individual integrations over when it suits your team, without affecting how any other route behaves. 

• Keep every existing integration exactly as it is. Routes that do not include the json suffix continue to receive application/x-www-form-urlencoded, exactly as they always have. 

• Build on a familiar payload structure. The JSON payload uses the same field names as the form-based payload, so adapting an existing integration typically means updating a parser, not rebuilding it. 

What you need to do 

To receive the new format, add json to the end of your route’s destination URL. The JSON payload differs from the form-based payload in a few respects: signature verification is provided through the X-Mailgun-Signature, X-Mailgun-Parent-Signature, and X-Mailgun-Timestamp headers rather than form fields; message-headers is delivered as a native JSON array; and attachments are consolidated into a single attachments array, with each entry providing filename, content-type, and base64-encoded content. Routes that do not include the json suffix are unaffected and continue to receive the existing format. 

Read the documentation 

Mailgun already meets your agent in the chat window via the Cursor MCP server and Claude Docs connector. The CLI meets it in the terminal instead: a new mailgun command for the contexts a chat-based tool cannot reach. This includes CI pipelines, cron jobs, scripts, and coding agents that operate entirely outside a conversation. 

The command surface is still growing, and we want feedback on what to prioritize next. Try it: 

npm install -g @mailgun/cli   

mailgun metrics summary --domain yourdomain.com --json 

Why does this matter? 

• Coding agents and CI systems that cannot hold an interactive chat session can still act on Mailgun. The same "check sending health" or "run a campaign preflight" logic behind the MCP Skills is now reachable from a shell script or pipeline step. 

• Every command outputs clean JSON. It drops straight into scripts, CI logs, or another agent's context without extra parsing. Pass --json on any command. 

• Nearly all commands are read-only. The one write command (preview run) requires an explicit --dry-run or --yes flag and never prompts, meaning behavior is deterministic even when an agent is driving it. 

• mailgun agent-context gives any agent a versioned, machine-readable map of the full command surface instead of one it has to guess at from --help text. 

Current coverage: Send metrics and live events, Validate, Optimize inbox placement, and Inspect email preview QA. Composite workflow commands like preflight and investigate are next. Your feedback on this release shapes which ones we build first. 

Found a bug or a rough edge? Open an issue on the mailgun-cli GitHub repo at github.com/mailgun/mailgun-cli. 

What's not affected: 

• Existing API, SMTP, MCP, and Skills integrations are unchanged. The CLI is an additional surface, not a replacement for any of them. 

• The CLI requires a Mailgun API key, the same as the MCP server. 

• preview run is the only write command, and it never runs without an explicit --dry-run or --yes flag and never prompts, so behavior is deterministic even when an agent is driving it. 

Mailgun now provides subaccount usage limit alerts for Messages Sent, Email Previews, Email Validations, and Inbox Placement Tests. If you're managing multiple subaccounts, staying ahead of usage is now a lot easier — primary account admins can set up alerts that notify them before subaccounts hit their monthly limits, so you can act early instead of cleaning up after an overage.
Alerts trigger at 50%, 75%, and 100% of a subaccount's configured usage limit. The 50% and 75% thresholds are editable to fit your workflow; the 100% threshold is fixed. Notifications can be delivered via email, Slack, or webhook.
To get started:

1. Go to Settings > Alerts > Accounts tab and enable the alert.
2. Configure your notification channels under Channel Settings on the same page.
3. Make sure a usage limit is set on the subaccount — the alert won't trigger without one. Configure limits via the Subaccount Management page, the Threshold Limits API, or the Custom Sending Limits API for sending limits specifically.

Mailgun Inspect is now live for Salesforce Agentforce Marketing — formerly called Salesforce Marketing Cloud Next

Mailgun Inspect is now available on Salesforce Agentforce Marketing. Once installed, Inspect embeds 100+ email client and device previews directly into Salesforce's Lightning Email Template Builder, so you can check how an email renders without leaving the template you're building. 

Why should I care? 

If you build emails in Salesforce Agentforce Marketing, this closes a gap in the platform: there's no native way to check rendering before you send. Here's what installing Inspect gives you: 

• Catch rendering issues before you send. Preview your Lightning Email Template across 100+ real clients and devices, including dark mode, right where you’re building it. 

• Stay compliant without extra tools. Run automated WCAG 2.2 and EAA accessibility checks on every template, especially useful if you’re sending to EU recipients. 

• Give your whole team access. Inspect has unlimited seats, so QA isn’t gated by who has a license. Anyone building templates can check their work. 

• Keep QA and delivery connected. Because Inspect is built into Mailgun’s email infrastructure, your rendering checks and your sending data live in the same place, not in two disconnected tools. 

What you need to do 

Find and install Mailgun Inspect from Salesforce AgentExchange to get started.

Until now, using Mailgun inside an AI coding agent or chat tool meant manual MCP configuration or pasting docs by hand. We've closed both gaps at once. The Mailgun MCP server and its 15 Skills are now listed in the Cursor Marketplace, and a Mailgun Docs connector is now available directly in Claude — hosted on our Redocly docs site, unauthenticated, and always in sync with our live API reference.

Why does this matter?

• Cursor users can install Mailgun as their agent's email tool in one click, with no manual MCP configuration. Read our help center guide.
• The 15 Skills cover the full Mailgun suite — Send, Validate, Optimize, and Inspect — so an agent can act on outcome-level prompts like "check my sending health" or "run a campaign preflight" instead of chaining raw API calls.
• Claude now has always-current access to Mailgun's API documentation, so it can help you build and debug integrations without relying on training data or pasted docs.
• The Claude connector requires no API key or Mailgun account — anyone can add it.

What's not affected:

• Existing API and SMTP integrations are unchanged.
• The Cursor MCP server requires a Mailgun API key to take actions on your account. The Claude connector is documentation-only — it surfaces API reference material but does not send email or access account data.

Phase 2 of Mailgun's IP management improvements is now live. Building on the centralized visibility introduced in Phase 1, you can now take action on your IP assignments without leaving the primary account. 

What's new: 

• Assign a dedicated IP to a domain, IP pool, or subaccount from the IP detail page. 

• Move IPs between accounts: reassign IPs from your primary account to a subaccount, or back again. 

• Multiple IP pools per account are now supported for non-dynamic IP pools. 

• Warmup improvements: the IP detail page now shows a timestamp for when the current warmup stage started and when the next stage begins. 

No action is required. Your existing IP assignments carry over automatically. Access the updated experience via "Dedicated IPs (New)" in your navigation. 

The Mailgun Inspect Chrome extension is now live on the Chrome Web Store. It opens a side panel next to your ESP’s email editor, pulls in the HTML for you, and returns renderings and issue reports from Inspect. 

Why should I care? 

You build email in your marketing platform. QA lives somewhere else. So you export HTML, toggle tabs, wait, and switch back to fix it. This extension is for email marketers and campaign managers who want QA without the tab toggle. 

• QA inside your ESP. Works with Mailchimp, Klaviyo, Braze, Constant Contact, BEE, and Mailviews. A full-page HTML fallback covers everything else. 

• No more copy-paste. The extension pulls the HTML from your editor for you. Previews and issue reports open right next to your work. 

• Know you’re testing the right email. A status badge turns green when the extension finds your editor, so you never preview the wrong page. 

• No sales call to get started. The extension is free to install, and a free Inspect trial gets you testing today. 

• Nothing runs until you say so. Your HTML only goes to Inspect when you click Run Preview. Your API key is kept for the browser session by default, or up to 30 days if you choose. 

What you need to do 

Add Mailgun Inspect from the Chrome Web Store and enter an Admin-role Mailgun API key. Domain sending keys won’t work, and the key must match your account’s region (US or EU). 

Your ESP setup doesn’t change. Results also land in the Inspect web app, where the HTML email editor lets you fix, version, and retest. Accessibility, link, image, code, and spam checks are included on Premium and contract plans. 

The Mailgun Inspect extension is now live on the Visual Studio Marketplace. Click the eye icon on any .html file and Inspect renders it across the devices and clients you choose. Results open in a panel right beside your code. 

Why should I care? 

You write email HTML in VS Code. QA lives somewhere else. So you copy the HTML, paste it into a web app, wait, and switch back to fix it. This extension is for email developers and engineers who want QA without the tab toggle. 

• QA in your IDE, not another tab. Generate previews from the editor title bar or the command palette. No copy-paste into a web app. 

• See real renderings beside your code. Previews across real email clients open in a panel next to your HTML, so you can fix and rerun fast. 

• Catch more than layout bugs. On Premium and contract plans, each run also checks accessibility, links, images, code compatibility, and spam. 

• No sales call to get started. The extension is free to install, and a free Inspect trial gets you testing today. 

• Nothing runs until you say so. Your HTML only goes to Inspect when you trigger a preview. Your API key is stored securely, never in settings.json. 

What you need to do 

See our full guide here.

You’ll need to install Mailgun Inspect (sinch.mailgun-inspect) from the Visual Studio Marketplace. Then run "Mailgun Inspect: Set API Key" and paste an Admin-role Mailgun API key. Domain sending keys won’t work, and the key must match your account’s region (US or EU). Requires VS Code 1.85 or later. 

Your plan and results history don’t change. Previews also show up in the Inspect web app. New to Inspect? Start a free 30-day trial. 

The dedicated IPs page has been redesigned from the ground up. Previously, understanding your IP setup meant navigating across multiple pages and piecing it together manually. Beginning mid-June 2026, every IP's warmup status, linked sub-accounts, linked domains, and IP pool assignments are visible from a single view — with filters to slice and search across all of it in seconds. 

Your IPs, sending configuration, and domains are not affected. This is a visibility upgrade only. 

Why does this matter? 

• See your full IP setup at a glance — warmup status, linked domains, sub-accounts, and pool assignments are now on one page, with no extra clicks required. 

• Find unassigned IPs faster — use filters to instantly surface any IP not yet linked to a domain, sub-account, or pool, so nothing slips through the cracks. 

• Jump straight to IP metrics — click "View IP metrics" from the IP list or any detail page to pull up a pre-filtered deliverability report without rebuilding filters manually. 

• Audit link history — the IP detail page now shows when each domain, sub-account, or pool was linked to an IP (for links made on or after April 23, 2026). 

No action is required to access the new page. Look for "Dedicated IPs (New)" in your navigation — your existing page remains available while you explore. 

Note: this is phase one of a broader IP management investment. Centralized IP assignment — letting you link IPs to sub-accounts and pools directly from the detail page — is coming later this quarter. 

Mailgun now offers a dedicated Forwards API for configuring inbound email forwarding. Now you can set up wildcard match patterns that forward incoming messages to recipients, URLs, or storage — purpose-built for recipient-based processing at scale. 

Here's what the Forwards API gives you: 

• Simpler configuration — Wildcard match patterns replace Routes' expression syntax, so you can define forwarding rules quickly without digging through docs to get the filter logic right. 

• Better performance at scale — Routes can slow down as your rule set grows. Forwards is designed to handle large rule volumes without the performance hit. 

• Cleaner separation of concerns — Save Routes for complex, multi-action processing. Use Forwards when you just need to get messages to the right place by recipient address. 

• Flexible delivery targets — Forward to individual recipients, a URL endpoint, or store the message — whatever fits your inbound processing workflow. 

Check out the Forwards API documentation to get started. 

Inbound Routes that post to a URL now include authentication results in the payload. This mirrors behavior for routes actions that send inbound email to defined mailboxes.  

Now users can:  

• Validate senders without extra work — Authentication results arrive with the payload, so you can check SPF, DKIM, and DMARC status in the same step as processing the message. 

• Build more reliable inbound workflows — Use authentication data to filter, flag, or route messages downstream based on whether they passed or failed — directly in your webhook handler. 

• Consistent behavior across routing types — Whether you're routing to a mailbox or a URL, you now get the same authentication detail. One less thing to account for when switching between the two. 

This update requires no changes on your end.  Authentication results will appear automatically in URL action payloads going forward. 

Mailgun Inspect now includes Gmail on iOS to its preview library. You can render your emails as they'd appear on iPhone 16 running iOS 18, in both Light and Dark Mode. 

Seeing your email through the Gmail iOS lens lets you: 

• Catch rendering issues before they reach the inbox — Light and Dark Mode can expose layout breaks, image inversions, or contrast problems that only show up on mobile. Fix them before your subscribers see them. 

• Test for one of the most common mobile clients — Gmail on iOS is one of the most widely used email environments. Previewing there isn't optional if deliverability and design quality are priorities. 

• Ship with confidence — Stop guessing how your email looks on your recipients' phones. See it yourself, in the actual client, before you hit send. 

The new previews are available in Mailgun Inspect now. 

Personally Identifiable Information (PII) redaction is now available as an opt-in setting in Mailgun. When enabled, sensitive data, including recipient addresses, is redacted from webhook payloads before they're sent. No post-processing is required on your end. 

The setting lives at the account level and cascades automatically to all associated domains and subaccounts. 

Why does this matter? 

• Reduce your exposure surface — Sensitive recipient data won't travel through your webhook pipeline, cutting down the number of places PII can end up at rest or in logs. 

• Simplify compliance — Whether you're working toward GDPR, CCPA, or internal data minimization policies, this gives you a cleaner path to limiting what gets stored and where. 

• One setting, full coverage — Configure it once at the account level and every domain and subaccount inherits it. No domain-by-domain setup required. 

To turn on PII redaction, go to Webhooks/Configurations tab to enable or disable the PII redaction feature.  

The Usage Report has been updated to give parent accounts a clearer picture of how usage is tracking, including limits and overages, at both the account and subaccount level. This applies if you're on a monthly plan or have monthly limits set for a subaccount. 

A few additional improvements shipped alongside this: 

• Limit and overage data is now included in exported reports 

• Date picker labels have been updated for consistency across the app 

Why does this matter? 

• Catch overages before they become a problem — You can now see overage data directly in the Usage Report, so there are no surprises at the end of a billing cycle. 

• Manage subaccounts without digging — Limit and usage data for every subaccount is surfaced in the same view, so you're not jumping between screens to get the full picture. 

• Export what you actually need — Overage and limit data now travels with your exported reports, making it easier to share usage summaries or feed them into your own reporting workflows. 

These changes are live and available in the Usage Report now. 

Mailgun's Delivered events now include the IP address of the recipient domain's MX host. When an email is successfully delivered, the MX host IP is surfaced directly in the event payload — no extra lookups required. 

For teams that monitor deliverability closely, every data point counts.

Knowing the MX host IP lets you: 

• Troubleshoot delivery issues faster — pinpoint exactly which receiving mail server accepted your message, making it easier to diagnose problems when something goes wrong. 

• Strengthen your logs and reporting — enrich your internal data pipelines with more granular delivery details for auditing, compliance, or analytics. 

• Identify patterns across recipients — spot trends in how different mail servers are handling your traffic, so you can tune your sending strategy accordingly. 

This update requires no changes on your end — the MX host IP will appear automatically in Delivered event payloads going forward. 

Mailgun now supports dark mode. If you prefer a darker interface — whether for comfort, accessibility, or just personal taste — you can turn it on directly in your account. 

The setting is stored as a cookie in your browser, so your preference is saved automatically each time you return. 

How to enable it:  

Head to your account settings and toggle dark mode on. That's it — your Mailgun dashboard will switch to a dark-mode color scheme right away. 

Mailgun has updated the signature payload for webhooks when an event occurs on a subaccount. When a webhook event fires on a subaccount, the signature payload will now include a parent-signature field that identifies the primary account. 

Previously, receiving servers needed to account for the unique signature of each individual subaccount to verify webhook authenticity. With this update, you can reference a single parent signature to validate events across all of your subaccounts, simplifying your verification logic. 

For more information, view the update documentation on securing webhooks.  

Mailgun has expanded the Mailgun Templates API with a series of quality-of-life improvements, including the debut of account-level templates. These improvements give you more flexibility and control over how you manage and send templates across your account. 

Key updates include:  

• Domain-level template improvements: The domain-level templates API now includes search, pagination, rename, and copy functions, making it easier to manage large libraries of templates at the domain level. 

• Account-level templates: You can now create and manage templates at the account level, allowing a single template to be used across any of your sending domains. This is the most flexible way to manage your template library and comes with the same quality-of-life functions: search, pagination, rename, and copy. 

• New Template ID: Both domain-level and account-level templates now include a unique template ID that can be used interchangeably with the template name when referencing a template during sending. This is especially useful if you rename a template — your code referencing the ID won't need to change. 

These updates reduce friction in template management and make the Templates API more robust for teams working across multiple domains. 

Mailgun now provides our valued partners the ability to set usage limits for subaccounts enabled with Optimize features including previews, validations, and inbox placement testing. Setting limits will allow customers to better monitor and charge their clients for usage.

Usage can be set in the user control panel via the Subaccount Management page or programmatically using the Thresholds Limits API.

Additionally, the Subaccount Management page has been updated to include additional metadata like Optimize feature statuses and limits for increased visibility.

Mailgun now allows users to create account level webhooks, simplifying setup for users who have multiple domains or subaccounts. Account-level webhooks will fire when an event happens on any of the domains belonging to that primary account or its subaccount(s). Domain-level webhooks will continue to only fire when an event happens for the domain it is configured for.

Additionally, we have added new domain name and account id fields, allowing you to identify which events are related to which domain/subaccount.

See more detailed information about the release here.

Mailgun has updated its domain verification service to support domains utilizing SPF macros, flatteners, and other Dynamic SPF records from providers like Valimail, Redsift, and Proofpoint. This update helps senders who use a single domain for many different applications.

Previously, those with complex mail streams could run into the 10 DNS record lookup limit for SPF.  Mailgun will now specifically check for the presence of these dynamic records and their validity during the domain verification process, giving you more flexibility in how you manage your DNS.

It's important to note that you will need to ensure proper configuration with your SPF provider to ensure that email messages will pass SPF checks by mailbox providers.

Mailgun Users can now set alerts based on the performance of their sending. Alerts can track a number of metrics (like bounce rate) by a specific dimension (e.g. a sending domain) and receive real-time notifications when that metric is outside your custom defined threshold.

Supported notification channels include email, webhook, and Slack integration.

The latest version of the Mailgun Zapier integration introduces a modern CLI foundation, new Validations, Alerts, and Route triggers that extend automation possibilities across send, validate, and inbound workflows.

• Email Validations: Validate single addresses or bulk lists directly within Zapier to improve deliverability and CRM data quality.
• Alerts: Receive real-time alerts for validation completions and deliverability changes (e.g., blocklist or reputation updates) without configuring webhooks in Mailgun.
• Routes & AI-Powered Automation: Use route-based triggers to handle inbound emails dynamically; filtering or prioritizing messages based on content or keywords. Combine with AI tools in Zapier to analyze sentiment, summarize customer intent, or trigger intelligent responses automatically.
• CLI Migration: Built on Zapier’s CLI platform for improved stability, rate limiting, and error handling.

Mailgun for Zapier delivers smarter, AI-ready email workflows that empower users to automate validation, monitoring, and response handling without writing a line of code.

Mailgun has enhanced bounce classification to provide deeper insights into email delivery failures. This update expands visibility beyond critical bounces and introduces new dimensions to help customers better understand and respond to delivery issues.

Key improvements include:

• Delay visibility: Critical temporary failures (delays) are now displayed alongside bounces, helping customers identify important delivery issues such as rate limiting that may signal more serious problems ahead.

• Criticality dimension: Bounce classification now includes both critical and non-critical bounces. Previously, only critical bounces were classified.

These enhancements provide customers with more complete data to monitor email health, troubleshoot delivery issues, and optimize their sending practices.

Mailgun’s Email Validations now provide a deeper view into the risk profile of your email lists with the following: 

• Accept-All Identification: Validate can now reliably detect when an email domain is configured as accept-all. These domains always return a “valid” response but, unlike catch-all, may result in a delayed bounce. 

• High-Risk Flagging: If an accept-all address shows no historical engagement data (no opens, clicks, or prior sending activity), Mailgun now flags it as High Risk.

Based on user feedback the Support role can now edit Templates on Mailgun. This will help lower the burden of needing to grant your designers developer-level access to work on you templates in the Mailgun UI.

User accounts can now designate a default region upon successful login.

Where previously Mailgun would produce Accepted events for a scheduled batch job at the time indicated in the schedule we are making a change that the Accepted events will generate at time of ingest in line with how non-batch scheduled messages are handled.

Mailgun now supports TLS client certificate validation for webhook traffic, providing an added layer of protection to a customer's receiving servers. All webhook requests from 'webhooks.mgsend.net' include a certificate issued by DigiCert, allowing receiving servers to verify the source of the request. Customers can validate the certificate and ensure the Common Name (CN) is 'webhooks.mgsend.net' before accepting the request.

User can now leverage the Mailgun API to enable or disable automated IP warm-up as well as check the status of the current stage the IP is in the warm-up process. For more information, please refer to our documentation <<https://documentation.mailgun.com/docs/mailgun/api-reference/openapi-final/tag/IP-Address-Warmup/>>.

We have seen an increase in open events which match our analysis of bot engagement for bot activity based on known user agents and egress IPs, but fall outside our timing window. To compensate, we have increased the timing window which will increase bot engagements related to Google Workspace hosted domains and consequently adjust organic open rates based on this change.

We have refreshed the subaccount management page that details more relevant data points for primary account users needing an organizational overview of their subaccounts.

You can now easily see subaccount status, user/domain/API key counts, IP/IP Pool assignments, and more, as well as filter by subaccount status and export the data as a CSV file.

We’ve introduced a new, dedicated interface for managing subaccount access to key features like Email Previews, Validations, and Inbox Placement. In addition, primary account users can now set Message Sending Limits per subaccount — giving greater control over message consumption for Contract Customers managing multiple subaccounts.

Now available for contract customers, Dynamic IP Pools automatically groups and manages domains based on reputation signals like bounce and complaint rates. This helps simplify deliverability oversight, reduce risk, and protect high-performing senders — all without manual intervention. Users will also have control to override or lock pool assignments as needed.

This feature is opt-in — to enable Dynamic IP Pools for your domains, visit the IP Pools settings page or set up via the Dynamic Pools API endpoint.

Mailgun has released our pre-send quality assurance suite – Mailgun Inspect. This suite will offer Accessibility Testing against the latest guidelines, Link & Image Validation, and Email Previews in over 100 devices (including dark mode).

When creating a new sending domain via the Domains API, the `smtp_login` field will not return a value as SMTP credentials are no longer generated automatically. To create SMTP credentials, use the Credentials endpoint or configure them in the UI under domain settings.

Mailgun now provides aggregate DMARC reporting in partnership with Red Sift.

• Aggregate DMARC Reports: Gain insights into email authentication and security with detailed DMARC reports.
• DMARC DNS Record Generation: Easily generate DMARC records as part of our DNS setup process.

These updates help improve domain security and email deliverability.

Mailgun now provides partners the ability to control customer access to key products like Email Validations and Optimize's deliverability tools. Enable or disable specific features at the subaccount level through both the Subaccounts API features endpoint and the ‘Manage Features’ override from the UI.

Mailgun has added the ability to pull account usage via the UI and API. These usage tracking reports provide real-time reporting on: 

• messages 
• Validations 
• Inbox placement tests 
• Email previews 

Usage consumption reporting includes the entire account, making it easy to forecast and manage consumption. Usage tracking reports are accessible via ‘Account Settings’ and ‘Plan & Billing’ within the UI, and programmatically via the ‘Analytics/Usage/Metrics’ endpoint.  

Users are now able to drill down from analytics into the associated logs. This is an incredibly powerful improvement to our reporting capabilities and positions Mailgun as the leader in reporting capabilities. 

New features alongside this integration include: 

• Users may export up to 1000 logs to a csv file. 
• Logs are no longer tied to domains, allowing users to view all logs for all domains in a single view. 
• Subaccount logs are displayed alongside parent logs. 
• Advanced filtering allows users to filter by 25 dimensions including user variables and delivery status messages. 

Admin users can now programmatically retrieve a list of user accounts via the Users API endpoint. All users can now retrieve their own user account details, and Admin users can make a GET call to return specific details for a user on the account.  

For more information on public API endpoints and access levels per role, please visit our documentation. 

By utilizing CNAME DNS records for DKIM keys, users can elect to have Mailgun automatically rotate their DKIM keys, offering additional sender security. Mailgun will create 2048-bit DKIM keys and rotate them once every 120 days, with the option to force rotate keys at any time.

Admin users can now programmatically create API keys via an API Keys API endpoint. This also includes the ability for an admin user to create a sending/domain API key using a primary account API key. Additionally, we made public our SMTP Credentials API and IP Allowlist (Whitelist) API. For more information on public API endpoints and access levels per role, please visit https://documentation.mailgun.com/docs/mailgun/user-manual/mg_security/#rbac-api-key-permissions-based-on-role.

Mailgun’s Analytics have been completely rebuilt. Utilizing OLAP cubes to power the backend, reports will now load quickly regardless of your send volume. Because of this performance improvement, you can now:

• Select up to 3 dimensions for your tabular data views
• Filter on multiple values and operators like “equals”, “not equals”, “contains”, and “not contains”.

Future forward, our analytics team will be working to rebuild the logs platform to integrate with our analytics solution, allowing for seamless analysis across features.

Introducing email health score, our proprietary scoring for email program success and improvement. Based on your account, IPs, domains, and emails delivered (minimum of 10,000 emails sent over the past 30 days), the email health score points to the areas of improvement with recommendations for detractor remediation. Points are based on health sending habits as well as bad ones, including high bounce rates, complaints, critical failures, and more.

We have released GZIP compression support on our /messages API endpoint. This allows API users to compress their API requests to send messages, thereby reducing network overhead and bandwidth costs.

Introducing Role-Based Access Control (RBAC) for API key users.  Previously, RBAC was implemented as a user management feature on our dashboard. Now, the RBAC concept has been applied to new API keys by giving an Admin user the ability to assign a pre-defined role that controls API access at the user level. This reduces the risk of account compromise, and provides more control over what API endpoints users can (and can’t) access.

We have added a new metric – ‘time_to_deliver_first_attempt’ - to the delivered event representing the time (measured in seconds) from the point Mailgun accepts your message send request to connection to recipient host for email transmission.

We have updated the navigational flow of the Mailgun UI to bring our Optimize and Validate products into a single app experience. This release also includes an in-app walkthrough of new navigation experience.

Validations Engagement Results attribute an engagement type to the email address that is validated. Through this, customers can segment their email list(s) based on engagement activity. This activity result is based on the past 30 days of engagement at the time of validation.

A primary account can now assign an IP pool from the primary to their subaccounts via the UI and/or API. Alongside this, the IP pool can be allocated to any sending domains on the assigned subaccount(s), as well as allowing for the assignment of the same IP pool to multiple subaccounts.

For outbound messages, we added the Mailbox Provider (displayed as recipient provider) to the event webhook payloads as well as the event logs in the Mailgun application. This will allow customers to analyze their sending performance per Mailbox Provider.

We have updated and modernized our publicly available help and API reference at https://documentation.mailgun.com/

We have updated our officially supported libraries to include subaccount API operations.

We have added ARC headers to all inbound email routed and forwarded by Mailgun. This change was implemented to better align with policy changes at Google and Yahoo.

Also, since we can retain authentication on the forward, DMARC compliance should be retained.

We have enhanced the header X-Mailgun-Sending-Ip-Pool to allow a subaccount to send via a primary account-level IP pool. This change was made to support a few different use cases but should remove the burden for primary account users to micro-manage IP allocation on the subaccount level.

Our new IP Allowlist now secures both API and SMTP connections to Mailgun. We have moved the feature into its own navigation item in the settings menu: IP Access Management. Additionally, you are now able to add your own description when creating a new list entry or by updating existing entries.

We have launched a new region switcher in the top navigation of the Mailgun application that quickly and easily allows users to switch between our US and EU region for managing assets.

For supported plans we have added filters and groupings for both subaccounts and IP Pools.

Mailgun has increased the max scheduling window for messages from 3 to 7 days. The scheduling window is based on the plan's message retention, i.e., Foundation message retention is 1 day, so the max scheduling window is 1 day. Scale message retention is 7 days, so the max scheduling window is 7 days.

We have officially released our long-anticipated subaccounts feature. We hope to assist a number of user cases that need self-provision and segment Mailgun accounts based on business unit, email type, or serving your own end-users. Please note that the subaccounts feature is currently reserved for contract customers.

Mailgun has launched a long-anticipated upgrade to our API key management system that allows the creation of multiple API keys for users who are managing multiple applications. We also upgraded the security of our keys, meaning they will be hashed in our database, and we will be unable to display them in plain text once generated.

Mailgun will now push an event data payload to your URL when Mailgun accepts the request to send/forward the email and the message has been placed in queue.

We have implemented changes to affect how Mailgun shared IPs are allocated to sending domains. When a sending domain is only using shared IPs, these IPs are no longer explicitly assigned to the sending domain. The sending domain will use shared IPs designated at send time. As such, the UI will not show explicitly assigned shared IPs. 

We have added the option to place a tracking pixel at top of email. This is to assist senders that may be sending large emails that are only being partially rendered/displayed at the recipient causing inaccurate engagement rates when tracking pixel is by default located at the bottom of messages.

See our documentation on the setting as well as an API reference on the new parameter.

We've launched the ability to manage up to 3 active DKIM keys for a sending domain which will allow a user to manually rotate their DKIM key, or upgrade their key(s) from 1024 bit to 2048 bit keys without having to delete and re-add a domain. See our Help Article here: How do I rotate my DKIM key? or our API docs at Domains — Mailgun API documentation for more information.

We've added the following updates to our Templates offering:

• Ability to store headers (Subject, From-address, Reply-to address) directly on a template, which will allow you to send a message providing just the recipient and template name.
• Removed limitations in template name that prevented the use of capital letters, spaces and special characters (template name is now encoded)
• Fixed an issue where templates that included some Handlebars helpers were not rendering in the Mailgun application.

Mailgun has released support for payment using EUR and GBP currencies. This will allow new users signing up to choose their preferred currency (USD, EUR, GBP) for billing purposes.

We've released the ability to view and manage linked domains on the Edit IP Pools modal located at https://app.mailgun.com/app/account/ip-pools/list.

Mailgun has retired the 'htmlonly' open tracking setting and has removed the option from our API and application. This was a legacy setting that had low adoption and should have an extremely low impact on customers.

We released a small update to our /ip_pools endpoint to allow a user to issue a GET call to https://api.mailgun.net/v1/ip_pools/<pool_id> to be able to retrieve information about the IP Pool such as which IPs and domains are associated with that IP Pool, along with the usual name and description.

UI updated to support manual creation of SMTP password when creating a new credential or resetting password for SMTP login previously created. While it is recommended to use the more secure, auto-generated password, some use cases needed the character count of the password to be shorter.

Fixed Resend message modal from Logs page to pre-populate original recipient address. Removed non-relevant placeholder text.