We have found that SM is apparently unwilling to send mail to one specific domain. I can connect to it using telnet so I know it isn't a blocking issue, and the DNS all seems fine, just any emails with this domain in the to address go into the queue and sit there, the attempts stay blank, the next attempt date never changes so it indicates a past time/date. I have restarted the SM service, and even rebooted the server, but the server seems to have not desire to even try sending them, Nothing shows in the logs it attempting to send them, only the smtp log shows them being received by the server.  We are currently running 13.2.5511, so maybe an update will fix it, but would like to know if that is likely before I schedule downtime for the update.