We run a VBScript through scheduled tasks on a Windows 2003 server that uses cdo.message to send mail to external email addresse via a relay set up on our Exchange 2010 server.
I have a Receive connector set up on the hub transport using an ip address assigned to one of the ports on a quad nic......different ip address than the server itself but still using smtp port 25.
We ran this process on our Exchange 2003 server and it worked fine, relaying on the average of 50 - 100 messages at a time in about 10 - 15 seconds.
Through the Exchange 2010 server, we may send out 4 messages successfully one day, 20 messages successfully the next day, 10 messages successfully the next, etc and then it just stops sending.. the scheduled task appears to be running but the mail send doesn't complete.
I found this Exchange shell command that fixed others having the same problem:
Set-ReceiveConnector "Connector Name" -MaxAcknowledgementDelay 0
....this appeared to have worked the first time we ran the process after I entered the command, but every time since it has bombed.
I also found a reference to the ESMTP Inspect parameter on the firewall that fixed a similar issue, but my problem still remains....
Any help\direction would be appreciated.....