mlist@??? writes:
> It doesn't even show up in the reject log (i forgot to mention that
> weirdness). Other things show up in the reject log though, so i
> don't think the reject log is broken per se.
>
> This is a typical response back when a user on the problem system
> tries to send mail to a user on my system:
>
> ----- Transcript of session follows -----
> ... while talking to theory.org.:
> >>> RCPT To:<mlist@???>
> <<< 550 relaying to <mlist@???> prohibited by administrator
> 550 <mlist@???>... User unknown
Hypothesis: between you and the calling system is a
transparently-redirecting firewall, which redirects the connection to
another Exim somewhere near the firewall. This Exim or firewall's
configuration is wrong, or the calling system's configuration is wrong
and it should be using some different system as a smarthost.
Proposed test: ask the calling user to `telnet theory.org smtp' and
see what the banner is (or get them to run their MTA with debug).
