Does anyone know what would cause Exim to reject recipient
addresses in incoming email with a temporary rejection when there is no
'verify = recipient' ACL in use ?
Recently, some of our Exim systems started rejecting all email to
external recipients. The problem started without any obvious cause, and
stopped after about an hour. The problem affected all our internal Exim
systems (7 machines), and the problem stopped on all machines within a
few seconds, suggesting that it was caused by some external event, such
as a DNS problem, except that there was no evidence of DNS problems or
any other network problems. Email sent to internal domains was not
affected. We have 'verify = recipient' for internal domains but not for
external domains.
The logs did not give any indication of the cause. The entries had the form:
2007-06-25 14:20:03 H=mac22.ucl.ac.uk [128.40.2.152]
F=<a.person@???> temporarily rejected RCPT <person@???>
Normally there is some additional explanation at the end of the log
entry, but not in this case.
The machines that were affected all had identical configurations, are
running a mixture of Solaris 8 and Solaris 10, are on several different
subnets, and are using Exim 4.63.
We have some other machines that have 'verify = recipient' for all
recipients, and these were not affected.
This is the second time that the problem has occurred in 6 months,
but on both occasions, it went away before we could investigate it
fully. There have been no recent changes to our Exim configuration, and
we have running Exim for a number of years without seeing this problem.
Has anyone else seen a similar problem ?
--
Adrian Barker, Information Systems
University College London, Gower Street, London WC1E 6BT
External phone: +44 20 7679 5140, Fax (+44) 20 7388 5406
Internal phone: x 25140
Email: A.Barker@???
