There is, fortunately, an ending to this query....
"I figured out the issue.? The invite system for??uses TLS 1.1 and most everyone has migrated to the newer version of 1.2.? However,??uses 1.2 for their normal group stuff.? My email provider only allows 1.2 while most allow 1.1 and 1.2."
Thank you all for your help.
Peter Keenan