I have logwatch running on a number of servers and have had a message within the sendmail section on one server for some time but as everything was working I figured it could wait. I finally took the time to check it out this morning and I was correct in my assumption.
[php]——————— sendmail Begin ————————
**Unmatched Entries**
STARTTLS=client, relay=mysmarthost.exchange.2007.server., version=TLSv1/SSLv3, verify=FAIL, cipher=AES128-SHA, bits=128/128: 9 Time(s)
———————- sendmail End ————————-
[/php]
The server is configured to send all mail from the linux server to our internal MS exchange server.
This message with the verify=FAIL is just saying that the CA authority for the certificate being used could not be verified. This is normal with self-issued certificates and is just a note.
From my perspective the main thing is that the count of X time(s) is higher than 9 on a normal day as it is our Kayako HelpDesk server and typically it is 300+ emails / ticket actions. So a low count indicates a problem.
Thanks to Alexander in the nginx forums for the pointer and link to the relevant sendmail details on starttls..