TOCICI

Broken Reverse DNS

You've been directed towards this page, because, while trying to email a recipient on this system, your email was bounced/rejected with a 554 error linking to this page.

Your email has been denied entry into our network, because your mail server fails to properly identify itself. This process is known as reverse DNS and associates your mail server's network (IP) address into a hostname, so can better identify who is attempting deliver email into our systems. Spammers commonly hide or forge their reverse DNS records to avoid detection.

  • Additional information can be found on Wikipedia.
  • MailChimp Also offers some excellent mail server configuration advice.
  • Additional DNS configuration analysis can be done using the excellent toolkit provided by IntoDNS.

How do you resolve this?

The solution is simple; your mail server is not blocked, or blacklisted by us, your email system is simply misconfigured. Once your email administrator properly configures reverse DNS (PTR records) for your mail server, you will be able to email us again.

When contacting your email administrator, you should include the error message contained in the email alerting you to this problem. That error message contains important information to help your email administrator resolve your configuration issue.

Who else does this?

Most major email service providers block servers with invalid or otherwise incorrectly-configured PTR records. Here's a few examples:

If your administrator cannot, or will not, fix this...

While the fix is quite simple, quick, and very straightforward to properly implement, if your administrator is unable or unwilling, we'd be happy to help.