Mailgun blog
Helpful articles to optimize your email program.
Designing HTML email templates for transactional emails
Styling HTML email templates is painful. Tables, inline CSS, unsupported CSS, desktop clients, web clients, mobile clients, and various device sizes are all things that influence...
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SMTP error codes and what they mean
SMTP, or
Simple Mail Transfer Protocol
, is the language servers use to talk to each other when sending emails. When something breaks during that conversation, the server returns a code to explain what happened. These
status codes
offer valuable insights, helping you figure out what went wrong and how to fix it...
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How to check email domain reputation
Sending good email isn't just about sharp copy or eye-catching design. If mailbox providers don’t trust your domain, your messages won’t land where they should. Domain reputation plays a big role in getting to the inbox, and too many senders ignore it until there’s a problem...
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What is an email MTA? A guide to mail transfer agents
In this guide, we’ll cover everything from the MTA basics to advanced strategies for building modern email infrastructure. Plus, we’ll give you actionable tips and ...
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Why accessibility in email isn’t optional anymore
Accessibility matters, not just because of legal requirements like the upcoming EAA (don’t worry, we’ll explain), but because it's the right thing to do. We’re recapping our latest episode of
Emails Not Dead...
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The golden age of scammers: AI-powered phishing
Long live the prince of Nigeria, he had a good run. Gone is the age where scammers wield the same mediocre power as a snake oil salesman, reliant on their own persuasion and...
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Help! My email needs a correction: What to do after you’ve already hit send
Whether you’re a seasoned pro or a first time sender, if you send emails chances are you’ve experienced the regret of the send button. You thought it was a flawless email, so...
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The 7 best email verification tools (and why devs choose Mailgun)
When it comes to email, deliverability isn’t just a “nice-to-have” it’s mandatory - especially since inbox providers are enforcing stricter requirements. If you’re sending to bad email addresses, you’re risking your sender reputation, delivery rates, and ultimately...
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Why DMARC matters more than ever: Email’s Not Dead season 6 ep. 1 recap
Email authentication has been a foundational part of email deliverability for years. But 2024 marked a turning point, as mailbox providers like Gmail and Yahoo began enforcing stricter requirements for bulk senders. The latest episode of
Emails Not Dead
explores what’s next for senders...
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The 5 best email API services in 2025
In 2025, email APIs are critical for businesses aiming to automate large-scale communications while ensuring top-notch deliverability and compliance. Developers and marketers alike need solutions with reliable infrastructure, developer-friendly tools, and integrations to support...
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