Sean wrote:
> Hello all,
>
> I have been having problem receiving email from a certain mail server. Our
> mail server is a postfix on Suse Open Exchang Server 4.1. The emails are not
> accepted by our mail server at all. Here is the error we get on
> /var/log/mail
>
> Apr 2 12:23:47 postfix/smtpd[28018]: connect from *****.ca
> Apr 2 12:28:47 postfix/smtpd[28018]: lost connection after EHLO from
> *****.ca
> Apr 2 12:28:47 postfix/smtpd[28018]: disconnect from *****.ca
>
> The other party gets an error 4 hours later "a 451 read error". They don't
> get a bounce back, the mail servers never able to communicate at all.
>
> We don't have any problems with any other mail server. It is just this
> certain host.
>
> Any is heavily apreciated.
>
> Thanks and have a nice day.

First of all, since your server has no problems with any other servers, the
odds are increased that the problem is on their end rather than yours.

Your mail server is reporting a lost network connection after 5 minutes. It would
appear that their server doesn't realize it until 4 hours later.

This is most likely a network related issue.

The best place to diagnose this would be on their end, using their email log files, or
a network sniffer to watch what's really going on.

But you might be able to spot something from your end by increasing the
logging verbosity of smtp in master.cf, or using tcpdump or ethereal when they
connect up.
--
Greg