I am having the same problem. New install and new SQL DB. My users are frantic.

The Exception error *may* not be related to the emails not being sent.

SpamFilter checks the quarantine database every 5 seconds to see if there are any emails to be delivered. The query that makes this check has a very "aggressive" short timeout, as we do not want to waste too many resources. If it timeouts once, it will be executed again after 5 seconds, so it's usually not a big deal. Often you'll see dozens of those timeouts thrughout the day. Unless you see hundreds or thousands, it's nothing to worry about.
 
Going back to the original problem about not being able to deliver the emails, to see what is happening we'd need a copy of SpamFilter's activity logfile, possibly trimmed to include a few minutes before and after the time the quarantine emails was being delivered. Please also include the from/to email addresses involved so we may locate them in the logs.

Increasing the "MiscSQLTimeout" setting will indeed increase the timeout for the query that checks the quarantine for any pending emails to be delivered, but again, unless the error appears continuosly, there should not be a need to increase it.
 

We had to up the time again so I think we may need troubleshoot further. I am adding memory to my MSSQL server as it a little low. I will test the quarantine issue once it has been running for a while and I will get a copy of the log and PM it to you.

 

Thank you