Intermittent sendmail problems for users

[Donald Tyler]

Today we have started to have intermittent problems accessing our email 
server. No changes have been made to the server, and I have absolutely 
no idea why this just started happening.

The problem occurs 99% of the time, occasionaly allowing someone to 
send or receive every now and then. The problem manifests itself on the 
clients as a continual prompt for the account passwords. We are using 
Mac OSX Mail & M$ Outlook (On the PC's).

Here is an excerpt from the maillog file. I don't understand what this 
means or how to fix the problem, and would greatly appreciate some 
help.

----------------
Aug  3 10:29:06 mail sendmail[1085]: i73FSxrP001080: 
to=<dtyler at frazerbilt.com>, delay=00:00:03, xdelay=00:00:00, 
mailer=local, pri=54537, dsn=2.0.0, stat=Sent
Aug  3 10:29:07 mail sendmail[1084]: i73FT4rP001084: [10.0.0.166] did 
not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
Aug  3 10:29:10 mail ipop3d[1087]: pop3 service init from 10.0.0.166
Aug  3 10:29:13 mail ipop3d[1087]: Command stream end of file while 
reading line user=??? host=[10.0.0.166]
Aug  3 10:29:18 mail sendmail[1088]: i73FTFrP001088: [10.0.0.166] did 
not issue MAIL/EXPN/VRFY/ETRN during connection to MTA
----------------


Thanks in advance.



Donald Tyler