Outbound SMTP Port 25 Redirect to Another Port



  • Hello All,

    I have a Dell PowerEdge Server with IDRAC6 Card, that has port SMTP 25 hard coded, cannot be changed. I just spent last 4 hours searching for a solution. I do not have internal server, and i cannot find any external Outbound SMTP servers that still have port 25 open.

    What i am trying to do is reverse Port Forwarding/Redirection on outgoing instead of incoming. I want to take any traffic that comes from Internal IP Port 25 and send it out same but only on port 26 or 465, 587 etc.

    Any Help would be appreciated. Settings are so limited in IDRAC6 that i cant do much, no authentication nothing.

    Running:
    2.0.2-RELEASE (amd64)
    built on Fri Dec 7 22:39:43 EST 2012
    FreeBSD 8.1-RELEASE-p13

    Thank you.


  • Rebel Alliance Developer Netgate

    The problem is that if it does not support authentication, you may not find anything that will take the mail on another port. Many places block 25 from users now and only allow 587 (submission) but that requires authentication to work.

    The actual redirect you can do with a port forward, e.g.

    Interface: LAN
    Protocol: TCP
    Source: The iDRAC IP
    Destination: Any
    Destination Port: 25
    Redirect Target: the mail server you want to use
    Redirect Target port: The port used for SMTP on the target server



  • I am using my personal hostmonster email and they use Port 26 and allow sending with no Authentication.

    I will try to do what your saying.

    I was under impression that worked only for Incoming Port Forward/Redirect not outgoing.

    Thank you.


  • Rebel Alliance Developer Netgate

    @prometheus:

    I am using my personal hostmonster email and they use Port 26 and allow sending with no Authentication.

    That should be OK then.

    @prometheus:

    I was under impression that worked only for Incoming Port Forward/Redirect not outgoing.

    Technically it is still incoming, it's just incoming to the LAN, not incoming to the WAN. :-)

    That kind of rule is what other things use to grab traffic, such as squid.



  • Just an idea… You could install esxi on the box and virtualise Pfsense  ;D



  • Thank you for suggestion, i have tried it and tried tweaking it few times, but no luck.

    Rule is setup exactly as you described it. I had to create alias to specify Redirect IP so it goes to URL instead of IP because it might change.

    No luck.



  • Port 25 is still the server to server port. Its the ISP (client side) that blocks port 25.

    Idea 1- Make destination ip any.

    Idea 2- Try redirecting from port 587 (client) to port 26 (their server) if they really have it open.  You need to find out what its open to.

    The idea of an email server allowing connection to port 25 for anything else other than email coming from another server for delivery to its clients makes it sound like an open relay.

    Wouldn't it be the client device/software behind your server that is doing the authentication to the server? If Im not missing something try port 587 out the door or even IMAP (146).

    Unless your trying to get some program on the server (IDRAC6) to email out??…