[exim] email queue build up

I am running Exim 4.67. No changes in Retry section of Configuration
file.



Exim relays email to Exchange Connector servers. tus1xchecnpin1/2/3 are
on the same local subnet as Exim. These Exchange connectors have higher
priority in MX recors.



Mail queue on this server build up very often.

"./exim_tidydb -t 0d /var/spool/exim retry" It looks that removing the
locks speed up email delivery but in some cases email queue goes down
without any intervention.



How can I diagnose and fix the problem.



Thanks.

Mike.





T:tus1xchecnpin03.enterprise.veritas.com:155.64.230.20 32 77 Broken
pipe

09-Aug-2008 22:33:48 09-Aug-2008 22:33:48 09-Aug-2008 22:48:48

T:dub1xchecnpin02.enterprise.veritas.com:166.98.48.152 -18 77 Remote
host dub1xchecnpin02.enterprise.veritas.com [166.98.48.152] closed
connection in response to sending data block

09-Aug-2008 22:33:48 09-Aug-2008 22:33:48 09-Aug-2008 22:48:48

T:tus1xchecnpin01.enterprise.veritas.com:155.64.230.18 32 77 Broken
pipe

09-Aug-2008 22:33:48 09-Aug-2008 22:33:48 09-Aug-2008 22:48:48

T:tus1xchecnpin02.enterprise.veritas.com:155.64.230.19 32 77 Broken
pipe

09-Aug-2008 22:33:48 09-Aug-2008 22:33:48 09-Aug-2008 22:48:48

T:punaxchecnpin01.enterprise.veritas.com:10.217.161.21 32 77 Broken
pipe

09-Aug-2008 22:33:48 09-Aug-2008 22:33:48 09-Aug-2008 22:48:48

[root@???:/usr/local/exim/bin]