Gmail Now Tells You Why An Email Was Marked Spam

    March 20, 2012
    Josh Wolford
    Comments are off for this post.

Not everyone delves into the dark depths of their Gmail spam folder, but for those that do: Have you ever wondered why Gmail marked a particular email as spam?

Now you can easily find out, as each email marked as spam now displays a little message box at the top that explains to you why it was thrust into your spam folder.

The Gmail team announced this on their blog Monday evening:

Starting today, we’ll be showing a brief explanation at the top of each of your spam messages. Simply look at any message in your spam folder and now you can find out why it was put there and learn about any potentially harmful content within the message.

We hope that this is not only interesting, but also helps you learn about scams and other harmful messages that Gmail filters out. Whether you prefer to leave your spam folder untouched or do some educational digging, the information will be there for you.

Gmail will display a variety of different messages for why an email was marked as spam. For instance, I just got one that said “Be careful with this message. Similar messages were used to steal people’s personal information. Unless you trust the sender, don’t click links or reply with personal information.”

Or it might say, “Why is this message in Spam? It’s similar to messages that were detected by our spam filters.”

Other reasons that might arise involve Gmail being unable to verify the authenticity of the sender, or multiple other users having marked similar messages as phishing scams. If you click learn more, you’ll be taken to a Gmail help page with more information on spam emails.

  • http://www.aptivate.org Chris Wilson

    We spent a LONG time trying to figure out why our emails were being marked as spam by gmail. This message is simply untrue: the cause in our case had nothing to do with “similar messages being marked as spam”, and was because our new mail server has IPv6 support but no forward DNS to IPv6.

    I’m posting this here to help anyone else suffering with the same problem to find the answer more quickly than we did. Since our Linode came with ipv6 support built-in, and Google now supports IPv6, our smtpd was automatically using IPv6 to talk to Google. Google doesn’t like this because a reverse lookup on the IPv6 address doesn’t work, because we haven’t added a forward AAAA record, because our DNS host won’t let us. In the end we had to disable IPv6 support in Exim to stop it talking to Google using IPv6.

    From this well-hidden answer: https://support.google.com/mail/answer/81126

    Additional guidelines for IPv6

    The sending IP must have a PTR record (i.e., a reverse DNS of the sending IP) and it should match the IP obtained via the forward DNS resolution of the hostname specified in the PTR record. Otherwise, mail will be marked as spam or possibly rejected.

    The sending domain should pass either SPF check or DKIM check. Otherwise, mail might be marked as spam.