We have 2 gmail accounts in Thunderbird. outgoing emails don't show in sent mail. I read the solution for my same problem- quoted below. This does not fix the problem for me. Every time I change the SMTP outgoing address for one account the other account gets changed to match it. "It is exactly as I suspected: all the SMTP servers have the same description. To fix the problem, you need to edit each of them in the account settings>Outgoing Server (SMTP) pane and give each a different DESCRIPTION. Since they all have the same name, Thunderbird goes with the default. I suggest putting each email id within the description field for easy identification. Do that for all four SMTP servers. Then, click the account page for each, and at bottom of pane, click and set the appropriate SMTP server.