Why my email keeps sending on spam?

Here are a couple of things to keep in mind when creating content, in addition to making sure it’s something people will want to read.

To check how your content is being judged by spam filters, you can create a test mailbox with Mailgun and enable their spam filters to receive a “spamicity” score. This is a helpful trick to ensure your content isn’t getting marked as spam.

  • Personalize your emails by addressing each recipient by name and tailoring the content to their interests and usage patterns. Mailgun offers recipient variables that allow you to create highly personalized email templates.

  • Use both text and HTML or just text when sending multi-part emails. Avoid sending emails that are HTML-only as they may not display correctly, especially if images are blocked by default. You can test how your email will look across different email providers and web browsers using tools like Litmus or Return Path.

  • Keep your text-to-link and text-to-image ratios high to avoid triggering spam flags at ESPs.

  • Avoid misspellings and spammy words like “buy now!” or “free!” as they trigger spam filters. Also, using all caps and excessive exclamation marks (!!!) should be avoided as they are also considered spam flags.

  • Use matching domains in the from field, return-path, and message-id when sending emails.

  • Include unsubscribe links and headers in your emails. Some email service providers (ESPs) like Hotmail prioritize these and may filter your emails if they are missing. To make things easier, you can use Mailgun’s auto unsubscribe feature instead of handling it yourself.

  • To avoid Gmail flagging your emails as spam, it’s important to ensure your Message ID and Received headers are correct. Incorrectly formed Message IDs (without brackets and with the wrong domain after @) can trigger Gmail’s spam filters.

    One easy solution is to skip creating a Message ID and let Mailgun generate one for you. This ensures a properly formatted ID that won’t be flagged as spam.

  • Include the sender’s domain in the links. Avoid using popular URL shorteners as they’re often used by spammers.

  • Optimize recipient engagement by A/B testing your emails. Use Mailgun’s tagging and tracking statistics to measure A/B testing, especially with subject lines, and improve your content.

For email best practices – Mailgun API documentation

If you have any questions or encounter issues, just email us at [email protected]. We’re here to help you in any way we can.