Pegasus Mail & Mercury

Welcome to the Community for Pegasus Mail and
The Mercury Mail Transport System, the Internet's longest-serving PC e-mail system!
Welcome to Pegasus Mail & Mercury Sign in | Join | Help
Home Blogs Forums Downloads Pegasus Mail Overview Mercury Overview Wiki

Reverse DNS check

Last post 04-03-2019, 17:08 by PaulW. 1 replies.
Sort Posts: Previous Next
  •  03-31-2019, 13:10

    • Anaglypta is not online. Last active: 29 May 2019, 12:03 Anaglypta
    • Top 500 Contributor
    • Joined on 09-30-2016
    • Luton, England
    • Member
    • Points 345

    Reverse DNS check

    Morning all,

    Is there any way to perform a RDNS check in MercuryS.

    What I want to do is check the HELO/EHLO text against RDNS and if they don't match, reject the connection since most email servers provide a FQDN as the HELO/EHLO command.

    i.e This IP has no RDNS info:-

    Connection from
    T 20190331 103329 5c59bad3 EHLO
    T 20190331 103329 5c59bad3 STARTTLS
    T 20190331 103330 5c59bad3 EHLO
    T 20190331 103331 5c59bad3 MAIL FROM:<> SIZE=247690

    Checking RIPEstat the IP resolves to an address in jakata with no RDNS

    I've looked at the SmtpEvt module, but didn't find anything that might help. It might be a good addition though.

    GreyWall works well to remove a lot of instances, but a few still get through.

    Thanks in advance



  •  04-03-2019, 17:08

    • PaulW is not online. Last active: 28 Jan 2020, 2:58 PaulW
    • Top 10 Contributor
    • Joined on 05-08-2007
    • UK
    • SuperStar
    • Points 18,475

    Re: Reverse DNS check

    That would be a good option to check.

    Another would be to see if the FQDN in a HELO resolves.


View as RSS news feed in XML

Contact | Advertise | Host provider: PraktIT | Terms of Use | Privacy Statement
Copyright © 2007-2011 David Harris / Peter Strömblad. | Pegasus Mail Home Page