The Community Forums

Interact with an entire community of cPanel & WHM users!
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Direct mail traffic to certain ports?

Discussion in 'E-mail Discussions' started by meeven, Apr 28, 2009.

  1. meeven

    meeven Well-Known Member

    Joined:
    May 8, 2007
    Messages:
    124
    Likes Received:
    0
    Trophy Points:
    16
    Is it possible in cPanel/WHM to direct mail traffic for certain domains to one port and for other domains on another port?
     
  2. WebScHoLaR

    WebScHoLaR Well-Known Member

    Joined:
    Dec 14, 2005
    Messages:
    511
    Likes Received:
    2
    Trophy Points:
    18
    Location:
    Planet Earth
    AFAIK, cPanel/WHM doesn't offer any such feature.
     
  3. cPanelDavidG

    cPanelDavidG Technical Product Specialist

    Joined:
    Nov 29, 2006
    Messages:
    11,279
    Likes Received:
    8
    Trophy Points:
    38
    Location:
    Houston, TX
    cPanel Access Level:
    Root Administrator
    Can you elaborate on what you mean by "mail traffic." Are you talking about SMTP, IMAP, POP3, Webmail ...? By "another port" do you mean plain text vs. SSL port or something else?

    If you can provide some information on what you intend to accomplish, perhaps we may be able to help you.
     
  4. meeven

    meeven Well-Known Member

    Joined:
    May 8, 2007
    Messages:
    124
    Likes Received:
    0
    Trophy Points:
    16
    Thanks for asking and sorry for the lack of details.

    I meant incoming mail for domains on a cPanel VPS. The problem I am facing at the moment is that some clients who take hosting with me use a third party spam filtering service. However, they also find spammers bypassing the filtering by sending directly to their mail servers. To avoid this, they ask me to lock down incoming mail for their domains to accept incoming email only from the specific IP addresses that do the filtering.

    The issue is that, if I do this, other domains on the VPS will have their incoming mail blocked. I was wondering if there might be a way in Exim to specify certain domains (the ones using the filtering service) to use specific ports - meaning, Exim would run on those additional ports - and have the non-filtering domains run on the regular Port 25.

    I could then set a rule in the firewall to deliver incoming mail for specific domains to the additional port on which Exim is running. Ideally, it would be great to do this in Exim itself instead of the firewall.
     
    #4 meeven, Apr 28, 2009
    Last edited: Apr 28, 2009
  5. cPanelDavidG

    cPanelDavidG Technical Product Specialist

    Joined:
    Nov 29, 2006
    Messages:
    11,279
    Likes Received:
    8
    Trophy Points:
    38
    Location:
    Houston, TX
    cPanel Access Level:
    Root Administrator
    You could easily have Exim running on an additional port by going to WHM -> Service Configuration -> Service Manager and enabling the option for "exim on another port."

    However, the trick would be to filter the messages such that incoming mail over port 25 do not reach the client's email accounts.

    Something you may want to keep in mind is some servers do sender verify checks to curb spam. If you block port 25 traffic, sender verify could fail and messages sent from emails where port 25 is blocked may fail to reach their destination.
     
  6. meeven

    meeven Well-Known Member

    Joined:
    May 8, 2007
    Messages:
    124
    Likes Received:
    0
    Trophy Points:
    16
    Thank you, cPanelDavidG

    I got some help on the exim mailing lists and here is the suggested ACL:

    I checked the Exim configuration editor and there is only one line that contains acl_smtp_rcpt. The bigger problem is that I don't know the correct syntax for making this suggested ACL work - I can't possibly put those three lines into the Exim config editor and hope for it to work. It's more likely to bring the whole server crashing down.

    Is there someone here who could fill out this ACL for me? Or is this something for which I can submit a ticket to cPanel ?
     
Loading...

Share This Page