[cobalt-users] RaQ3 - Email problem false user unknown error

["Dave Reid" <daver1@xxxxxxxxxxxxxxx>]

I have a strange problem with sendmail.
For no apparent reason email addresses that a user could send to from
their account on our server previously, suddenly started kicking back
user unknown errors. If they send through their ISP or hotmail, etc.
then the email goes through with no problems. This is not just with
certain accounts on our server, once an address starts generating this
error, no-one on our server under any domain can send to that email
address. It started with one or two, but seems to get worse almost
daily. I have check my logs, and hosts.deny files and can find no
reason for this. I have also checked the sendmail.cf and sendmail.cw
files to see if they were corrupted, but everything looks fine. We
also have portsentry and sendlog installed. I have all the latest
updates installed from cobalt, although this started happening before
I installed the December 13 2002 updates. I am not sure if it is
related, but occassionally I get time-outs on retreiving email,
although I am usually checking about 13 different accounts at the same
time, so I always attributed the time outs to that, plus the fact I am
running MS Outlook behind Exchange.

Here is a copy of the error message I am getting back.

********** begin error message **************
Your message did not reach some or all of the intended recipients.

      Subject:	testing
      Sent:	1/15/2003 1:14 PM

The following recipient(s) could not be reached:

      kpodmore@xxxxxxxxxxxx on 1/15/2003 1:14 PM
            550 <kpodmore@xxxxxxxxxxxx>... User unknown
********** end error message *************

I have searched the archives and found nothing directly relating to this
problem, I am at my wits end. Please Help...

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