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smtpmail-serverreverse-dns

SMTP Reverse DNS Mismatch issue

According to MXToolbox my server has a problem.

Please review: https://mxtoolbox.com/SuperTool.aspx?action=smtp%3awebmaus.net&run=toolpage

The tool shows a 'SMTP Reverse DNS Mismatch' and I don't have an idea why. My PTR Records look like:

158.22.202.116.in-addr.arpa. 86400 IN   PTR     158.22.202.116.pleiades.webmaus.net.

I've also got A/AAAA records added for pleiades. Any hints on where the problem could be?

Solution

  • Reverse DNS: closed PTR-A loop

    SMTP servers check "closed loop" of PTR and A records.
    IP address -> [ PTR record ] -> Name -> [ A record ] -> IP address
    Rogue nets can set PTR to any name they like.

    There seems to be no A record for 158.22.202.116.pleiades.webmaus.net.