Given the problem started after updating to latest AVAST Free version on 3/1, with no other 'changes' (and on 2 pc's) it seemed appropriate to look there for the culprit. After finally determining that turning off the outbound mail shield, and outgoing mail working again, that seemed logical. After 5 days, after the uninstalls, installs, etc, turned outgoing mail shield back on. Outgoing mail working again. Maybe there was an AOL mail server (which is what Frontier/Verizon uses) problem, after all. Still, very strange. HK, Thanks for your help.