I've set up my Gmail account for reading emails via IMAP and sending emails all with Mozilla's Thunderbird. I followed Google's directions on how to setup the client to work with Thunderbird. It reads the emails correctly but when I send emails I get: "An error occured while sending mail. The mail server responded: INCORRECT DOMAIN IN MAIL/RCPT COMMAND. Please verify that your email address is correct in your Mail preferences and try again." As it suggests I check the outgoing mail setting and try again with the same results. Has anyone else run into this issue and how did you resolve it?