Can't send mail to netsolmail.net

The tech contact from jtecounsulting has been in contact with Network Solutions and they say there is no issue on their end, but as with most large corporations I would expect them to come from the position that the problem isn't their fault unless there is evidence to the contrary (and sometimes not even then.

I can telnet to their port 25. And while testing yesterday I did get a message through, but all the others eventually age out of the queue. I adjusted the main.cf to add debug peerlist = 205.178.149.7 and had to bump debug peerlevel = 7 to get it to log the full conversation between the server (I can't find any info on what to set debug peerlevel to other than default of 2 which didn't seem to have any effect on logging levels). It was after I did this that the mail actually went through.

I'm using a SonicWall and it shows the connection open and close but no other indication of an issue. I have had another test message that was delivered about 10 minutes after the original "lost connection" attempt, but another that is still in the queue after an hour.

postsuper didn't have any effect, but postfix flush did. In other testing I have had a message delivered after a 20 minute delay after the first connection, and one that went through on the first connection. I have a suspection something has changed on their end, as I haven't done anything on my end other than up the debug level.