OK, found two so far:

1) If you enable Premium antispam (which works awesome), it will ALWAYS insert X-IMAIL-Premium into the subject line no matter if it's set to do so or not.

2) I can log into the primary host's web messaging just like before, works great. But logging into any other domain's web message is Slow slow slow slow - it can take over 1 minute before it acknowledges the login, then it seems to work fine. If I enter a wrong username or password it responds immediately so it's not the user look up.

This is all I've got so far... anyone else? (8.20HF1 in place)

db