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Alternate port for SMTP

MillardJK
I've been using an alternate port for SMTP in conjunction with an upstream anti-spam/anti-virus service. The advantage has been multiple: crap traffic that relies on the MX record never finds its way to my WAN link, and crap traffic that randomly selects my WAN IP never gets past the firewall because I block all inbound traffic on port 25.

I will continue to use my external filtering service, but I'd really like to get some assistance in configuring the ASG to proxy for me on inbound messages; I can't see where the mail proxy could be configured for a different port for use in a situation like mine.


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  • 0
    I agree with points made by both you and Barry.  This is how your DNAT should look in order for you to have what you want with the most reliablility:

    Network Security\DNAT/SNAT
    New Nat rule
    Name:Mail

    Traffic Source: Any
    Traffic Service: MySMTP
    Traffic Destination: External (WAN) Address

    Nat mode: DNAT

    Destination: [leave blank]
    Destination Service: SMTP



    Cheers - Bob
     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
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  • 0
    I agree with points made by both you and Barry.  This is how your DNAT should look in order for you to have what you want with the most reliablility:

    Network Security\DNAT/SNAT
    New Nat rule
    Name:Mail

    Traffic Source: Any
    Traffic Service: MySMTP
    Traffic Destination: External (WAN) Address

    Nat mode: DNAT

    Destination: [leave blank]
    Destination Service: SMTP



    Cheers - Bob
     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
Children
  • 0 in reply to BAlfson
    Now I understand why I thought it wasn't working for me: I would see the SMTP livelog appear to accept the message, but it didn't get relayed to my internal mail server (or so I thought). However, while working on this today, I was more patient and simply started working on other things.
    Lo and behold, here come the test emails, trickling in to my mail server.
    Now I wonder what I can do to improve the performance of the intra-ASG SMTP...
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