User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5) Gecko/20031007 Build Identifier: Mozilla Thunderbird 0.3 (20031013) I created an account called "Regular". The pop3 id is pop3.covad.net abd the smtp server is smtp.covad.net. When I create a new email and send it, thunderbird is trying to authenticate me using the email I address (email@example.com) rather than the user name given under server settings. firstname.lastname@example.org is a forwarding service hence covad will know nothing about it. Mozilla v1.5 email works fine without issue and Mozilla's email is setup the same way as Thunderbird's email. Reproducible: Always Steps to Reproduce: 1.create an email 2.attempt to send email 3. Actual Results: enter password for email@example.com pop up appears Expected Results: it should have shown my real firstname.lastname@example.org
see bug 90507 Have you ever tried to enter your password and see if it works? The string email@example.com shown in the password dialog is not used for login, just the username part is relevant. Set the correct username in "Account settings > Outgoing Server". This one is used when Thunderbird tries to login on the SMTP server.
*** This bug has been marked as a duplicate of 90507 ***