I started getting reports that some internal e-mails weren't making it to the recipient's mailbox and the sender does not get an NDR. This is a one server environment (well two if you count the frontend which hosts no mailboxes).
After looking at message tracking, the failed messages get stuck at "SMTP: Message Submitted to Categorizer". I searched around for this error, and it seems to happen most often in regards to external messages, with DNS errors present.
I started sending test messages to monitor in message tracking, and started to get lazy and did not type in a subject. And VIOLA! I discovered that it was the blank subject e-mails that weren't getting delivered.
We use Symantec Mail Security for antivirus and filtering. But there is no policy in there that prohibits blank subject messages (if this was actually blocking it there would probably be a log of the action but there isn't).
Any ideas?
I'm pretty certain I have sent no subject e-mails in the past without any issues.
TIA
After looking at message tracking, the failed messages get stuck at "SMTP: Message Submitted to Categorizer". I searched around for this error, and it seems to happen most often in regards to external messages, with DNS errors present.
I started sending test messages to monitor in message tracking, and started to get lazy and did not type in a subject. And VIOLA! I discovered that it was the blank subject e-mails that weren't getting delivered.
We use Symantec Mail Security for antivirus and filtering. But there is no policy in there that prohibits blank subject messages (if this was actually blocking it there would probably be a log of the action but there isn't).
Any ideas?
I'm pretty certain I have sent no subject e-mails in the past without any issues.
TIA