Author Topic: Top 4 Ways to Get Blacklisted  (Read 658 times)


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Top 4 Ways to Get Blacklisted
« on: December 08, 2014, 01:44:38 AM »
Top 4 Ways to Get Blacklisted

As part of our server support packages, we help a number of businesses get remove their IP from Gmailís blacklist.
Outdated applications, especially PHP apps, are the number one way hackers use a server to send spam.

In our investigations, the most common reasons why Gmail blacklists your server are:

    Compromised user account used to send spam.
    Web application exploit used to send spam.
    Bulk emailing from mailing lists, newsletters, forums & blogs (even if they are opt-in).
    Bulk forwarding of email to Gmail.

The four items account for about 95% of all spam cases we investigate

The first two are security issues. Poor passwords and outdated web applications are hacker favorites. In either case, a compromise can mean 10,000ís of emails get sent to Gmail in a matter of hours. Such a breach will certainly land your serverís IP on their blacklist.

Another source of blacklisting is notices from forums, blogs or newsletters. Even if the person subscribed to the email and you provide opt-out information, Gmail may still flag your email as spam.

Lastly, forwarding large amounts of email to Gmail can trigger a blacklisting. We see this when people forward email blindly to Gmail. They then mark the email as spam. The result is that your serverís sending reputation is penalized since it was the one that last sent the email. This is a commonly overlooked reason for blacklist inclusion.