I use a connector to force all outgoing traffic to my ISP SMTP server. I looked today and I saw that 45 emails were stuck in Que and emails were not being sent out. I restarted the machine, reset the connection, no luck. What fixed the problem was I choose the option on the connector to: USE DNS TO ROUTE TO EACH ADDRESS SPACE ON THIS CONNECTOR. That worked. What did I do? Can I leave this option?
I always had the other option checked - Forward all mail through this connector to the following smart hosts...and then I put in my ISP SMTP server. and that has worked thus far.
ALso What is the option DO Not allow public folder referrals? Should I leave that checked?