I have been using TB for several years and just upgraded to Ver 3.x. I
have several "named mail lists" in my address book that I use to mail
to groups of friends. In earlier versions all I had to do type the
mail list name into the To: line and then enter the subject and type
in my message then send the email on its way.

Yesterday I upgraded to 3.x and this no longer works. When I type in
the named maillist's name add a subject and type my message and hit
Send, I get an error message:

"An error occurred while sending mail. The mail server responded:
5.1.2 We were unable to find the recipient domain. Please check for
any
5.1.2 spelling errors and make sure you did not enter any spaces,
periods
5.1.2 or other punctuation after the recipient's email address,
2sm7083558qwi.17. Please check recipient "Joke List" and try again"

Same mail list - new version of TB. What gives?