[Mimedefang] SENDMAIL I/O error

[Eva Kolega]

   Hello.

We have integrated sendmail and trend micro for the needs of our domain 
(sendmail deamon runs in 2 instances).
The system  works in a perfect way but we seem to have 2 problems.
Actually, I have seen those problems in the list but I missed the answer 
if there was any.

1st problem:
Some few mails get stuck in the mail queue and their status is described 
as I/O error.
What could possibly be the reason for that ?

2nd problem:
We activated quotas for the /var/mail filesystem.
But when a user has exceeded his quota and a mail is sent to him as well 
as to other users (I mean of the same list), then the list users begin 
to receive this e-mail repeatedly ( every 4h for 5 days - in accordance 
to our queue settings). In spite of the fact that a user may not 
overquota, he will receive several times an e-mail just because he 
belongs to the same list-group with an overquota user.

I would apreciate any help on these two topics.

Thanks a lot,

Eva Kolega
Systems Administrator
NOC - TEI of ATHENS