Jump to content

ESET Mail Security on Exchange 2004 Not blocking Failed RDNS spam

Recommended Posts

Spam emails getting through with this headers:Received: from [] ([] RDNS failed) by mx.mail........com with Microsoft SMTPSVC(6.0.3790.4675);

I can't find a setting on Eset Mail Security / Antispam engine setup, or any other place, to deny path to failed reverse-dns domains.


Does it exist within this product? Or is it part of the mail server?

Link to comment
Share on other sites

  • 2 weeks later...
  • ESET Staff

hi ivanp74,

which version of EMSX do you use?

If you use 6.3+ then you can create a transport rule (Advanced setup/Server/Rules)
condition: Message headers contain "RDNS failed"
action: quarantine/drop/reject

If you use 6.4 then you can enable SPF

Link to comment
Share on other sites

  • 5 weeks later...





SPF enabled didn't stop Failed RDNS emails.

I had to add a rule under Rules / Mail Transport Protection

It works as expected now.


Thanks a lot!

Edited by ivanp74
Link to comment
Share on other sites

I'm starting to think blocking Failed RDNS is not such a good idea


"..from NAM02-BL2-obe.outbound.protection.outlook.com ([] RDNS failed) by..."



RDNS is failing in from those server and a few more legit senders.  


I was hoping to trap the spammers, but the net is too wide, need something smaller.

Link to comment
Share on other sites

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...