We're running into a problem on out outbound MEGs in how they are handling mail from Domino.
In the 6.7.2 world, mail would immediately be taken by the mail gateway. If it couldn't deliver it, it would stay on the gateway and go into retry state.
Under 7.6, if the MEG can't deliver the mail, it doesn't accept it and it stays on the Domino server. This is causing some problems as we've seen a backup of as many as 4600 messages. SO, our alert system shows email delays and it's not pretty.
I am assuming there must be someone already using 7.5-7.6 to route outbound mail from Domino. I know there is the option of setting the gateway up for store and forward. Are there other options?
We found another setting that we may try before that. Under Email Configuration - Sending Email - Queued mail delivery
There is a setting for Emails per connection. The McAfee consultant who was here for our upgrade set it to 5. We raised it to 10 one one of the appliances. That seems to be showing a significant decrease in mail queue buildup on the Domino servers. Instead of having 4500 messages backed up, we are getting a peak of about 400. Do you think this is another viable option?
Just got off the phone with a customer using domino as well and he was seeing the same problem. He tried to update this post, but he can't figure out how to log into his account on the forums(giggle). So I am updating it for him.
Domino by default will attempt to send as many messages in one connection as it can. in his case, I picked a random outbound message from the message search page on the MEG. It was message number 1,313 of the connection. At that point the connection had been open for approximately four hours. That was his delay and I am guessing yours is the same.
He also found this link that explained how to change the behavior of the Domino server: