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Email blocklist check

Want to improve your sending and email delivery? Blocklist check tools catch spam email problems before it becomes a serious issue – and before your server’s IP address or domain name is added to a spam database.

What is an email blocklist, and why does it matter?

No one wants to be on a blocklist, especially a business running email marketing campaigns. An email blocklist is a list of IP addresses and domain names flagged as sources of suspicious behavior, malicious content, and spam messages.

If your company’s mail server appears on an email blocklist or your email goes to a spam trap, it could put your email marketing efforts in the red. Inbox service providers might refuse to place your emails in your subscriber’s inbox after blocklist service providers flag your IP address or domain name for possibly sending spam.

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The search for spam

At all times of the day, organizations scour the internet to combat spam. These organizations collect details associated with suspected spammers and dump them into spam databases. If your IP address or domain name is listed in one of these databases, then you’ve been blocklisted. And you definitely don’t want to be on these lists.

Spamhaus is one of the top blocklists to worry about. As of May 2018, the nonprofit organization protected nearly 2.7 billion email inboxes worldwide. Its real-time threat and reputation lists block most spam and malware sent via email. Many internet service providers (ISP), email service providers, companies, universities, government agencies, and military networks use Spamhaus’s blocklist data. Globally, Spamhaus maintains a network of more than 80 public Domain Name System (DNS) servers that run billions of daily queries against DNS-based blocklists.

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5 reasons why an email gets blocklisted

Wondering how you ended up on a blocklist? Check out five common reasons why:

  • You’re suddenly sending out a large volume of emails

  • Your content looks spammy

  • Your account was hacked

  • Your subscribers have been marking your messages as spam

  • You purchased an email list (don’t do this!), and some of the emails are spam traps

How do I stay off of an email blocklist?

The best course of action is preventative action! Check out our list of best practices so you can avoid landing on an email blocklist:

  • Keep a healthy mailing list

  • Have clear opt-in and opt-out options, so your subscribers can unsubscribe instead of marking your emails as spam

  • Set up proper email authentication protocols so ISPs recognize your domain and don’t mark it as spam

  • Use email automation to send timely, personalized messages instead of bulk emailing (seriously, bulk emails are so ‘90s)

A graphic illustrating the statistics, deliverability rates, and engagement of emails.
Illustration of the statistics and delivery rate of an email campaign.

Why are email blocklist checks important?

So, how do you tell whether your IP address or domain name has popped up on an email blocklist? Perform a blocklist check. This check will determine whether your IP address or domain name has landed in a blocklist database. If you discover your IP address or domain name is on a public or private email blocklist, it could damage your entire email marketing campaign. Showing up on a blocklist affects whether email servers will allow your company’s emails to be sent to recipients or not.

Various tools are available to conduct blocklist checks. While your ISP should signal whether any of your IP addresses or domain names are on any email blocklists, things sometimes slip through the cracks. For instance, your email marketing messages could have mistakenly been marked as spam messages. That’s why it’s smart to use a blocklist monitoring tool to see whether your company has shown up on a blocklist. If the tool comes across your IP address or domain name, you can act quickly to remove your information blocklists.

Learn more today

Protect your reputation

Need help checking if you’re blocklisted? Our Managed Service runs ongoing checks and proactively monitors your reputation. This ensures your email marketing and transactional messages remain out of spam folders – and stay at the top of your current and potential customers’ inboxes. As a bonus, you’ll keep your email team happy and boost your marketing metrics!

Although Mailgun doesn’t provide blocklist checks within the control panel, you can use our logs feature to find the information you need for delisting.

Check out our plans to bundle features for better deliverability.


Explore beyond email blocklisting

Mailgun has a variety of features for companies in need of email blocklist tools.


How do I find out if my email is blocklisted?

Your ISP should signal whether any of your IP addresses or domain names are on an email blocklist, but sometimes they miss things. In this case, run a domain blocklist check on your email to see if your domain is on a blocklist. Check out Mailgun’s Blocklist Check Tool to see if your domains are on any blocklists. With this information, you can go back to individual blocklists to see why your emails are getting flagged.

How do I know if my domain is blocklisted?

At Mailgun, we help you monitor major blocklists in real-time. On the off chance you’ve been blocklisted, we step in on your behalf to help you get delisted and back to sending ASAP.

Can my email get blocklisted by Gmail?

Yes, you can get blocklisted by Gmail. To avoid this, keep an eye on your IP reputation with Google Postmaster Tools.

How do I unlist my domain if I’ve been blocklisted?

Don’t worry! It’s not the end of the world if you’ve been blocklisted. Check the instructions blocklist providers sent you if you were notified about getting blocklisted. Follow their steps to begin the blocklist removal process.

How can I prevent getting blocklisted?

Avoid getting blocklisted with these best practices:

  • Don’t purchase email lists

  • Don’t use ALL CAPS, poorly formatted HTML, lots of exclamation points, and all image emails

  • Maintain your mailing list hygiene

  • Perform email verifications before sending

If any of this is confusing, we’re here to help. As part of our Managed Service, we’ve automated monitoring all major blocklists to check them in real-time. Try Mailgun today, and our team of experts will have your back and step in to deal with the blocklist providers if necessary.

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