smtp-proxy problem

edited January 2020 in Firebox - Proxies

When an email is sent to a server behind the watchguard, from another site that is protected with another watchguard the mail server returns. said: 500
Syntax error, command unrecognized. In this article it says that it may be a smtp-proxy problem https://www.experts-exchange.com/questions/20741604/There-was-a-SMTP-communication-problem-with-the-recipient's-email-server.html
what is the problem?


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    If you look at the date of the posts, they are from 2003 & 2004.
    And one poster referenced a Firebox II.
    This would have been for a very old WFS version, probably V7.0.

    What firewall model and what XTM version are you running?

    Consider opening a support incident on this

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    RalphRalph WatchGuard Representative

    Hello Fer,

    The server is issuing an ESMTP command that either your proxy isn't configured to accept or the MTA is sending command in an unexpected order.

    You can use tcpdump** to capture the sequence. A set of arguments similar to below would work. -ni eth0 port 25

    This will capture all port 25 traffic, assuming the first NIC (eth0) is your external interface.


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