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Why did I receive the error "Not delivering to a user who marked your messages as spam"?

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    Ever received an avalanche of email from someone? Not exactly what you might call the most enjoyable experience. When this happens, we naturally might get tired of the sheer volume of emails and want to unsubscribe.  But what if the unsubscribe is ignored, or there isn't even a clear way to unsubscribe in the first place? Perhaps you're just fed up and want to end this madness right now?  You'll likely simply mark the message as spam to make a clean break. 

    Unbeknownst to you, that's exactly what your customer, Tim the Enchanter, did.  Tim received a ton of Black Friday emails from you this year and decided that enough is enough; spam button pressed! During your yearly Black Friday sale, you notice that sending to Tim is now encountering issues.  Being a savvy Mailgun user, you check your Mailgun Logs (or alternate monitoring method), and you notice Tim's email failed with the message "Not delivering to a user who marked your messages as spam." 

    So, what does this error mean; can Tim the Enchanter still receive emails from you?  Don't worry - we'll explain everything you need to know below!


    The problem

    If the recipient marks your message as spam, the rule is that you need to honor their decision of strongly rejecting your emails. The exception, however, is either if the recipient specifically reaches out to you stating the complaint was made in error, or if the recipient later opts-in to receive emails once again. In these specific cases, the recipient should opt-in once again to your emails and you may then remove their address from the Mailgun Suppressions list.  Removing the email address from the Suppressions list of the Mailgun Control Panel will allow delivery of new messages to said address.


    The cause

    This error indicates that the email address is currently suppressed by our system from further delivery attempts. Why? Because sometime after receiving one of your emails, the recipient decided they no longer wish to receive any further emails from you, so they marked the message as spam or junk in their email application.  When the recipient takes this action, their email provider generates a complaint and sends it to the sender's email provider (in this case, Mailgun).  When this happens, we suppress the address internally to protect the reputation of your domain, and that of our IPs. Additionally, we do this to comply with international laws and regulations. Sending to recipients who no longer wish to receive emails possibly violates numerous laws and regulations and severely damages your deliverability; this is spammer behavior, after all.


    The solution

    The solution depends on the reason behind the cause: did the recipient intentionally or unintentionally complain about your messages by marking them as spam?  Nearly always, the recipient's complaint is intentional. As such, you really shouldn't just remove their address from the Suppressions; you need to stop emailing them any further. (An important point: if the recipient opts-in to receive your emails once again at a later date, their address can be removed from the Suppressions list).  In some seldom-seen cases, the recipient's complaint is unintentional. When this happens, if they reach out to you explicitly stating the complaint was unintentional, the recipient should opt-in once again to your emails while you remove that recipient from the Suppressions.

    In the case that removing the address from Suppressions is warranted, you can remove them from the list via your Mailgun control pane, or via the Complaints API, using an HTTP DELETE request. 

    We'll show you how to do this below:

    1. First, log in to the Mailgun Control Panel (if you have not already done so).
    2. Then, within the left-hand navigation pane, click the Sending option to expand its list of suboptions.
    3. Next, click the Suppressions suboption.
    4. Choose the Complaints suppression type
    5. Check the box next to the specific suppression you would like to delete and then click the Remove selected button on the upper-right portion of the page (alternatively, clicking the Trash icon will accomplish the same result).

    Once removed, new messages that you send to the recipient will attempt delivery, rather than being suppressed.

    Lastly, to read more about Suppressions, please see this related help article.


    Need Support?

    Our Support Team here at Sinch Mailgun is happy to help! Reach out to us in the Support section of your Mailgun Control Panel, and we'll be with you shortly!