Gmail Problem with the outgoing email account in Thunderbird

For the past few days I was receiving emails from my friends in a totally different email than the one I was using to send from. I am using Thunderbird with 9 different email accounts. One of the problems of Thunderbird is that it can use only one smtp server for all your email accounts. That means that if you wish to hide your smtp server or use a different one for each account, you simply cant. A clever person can then guess that your smtp includes clues from your "real" email adress and there goes your anonymity. Anyway. The smtp trick is another thing, but to simply show as an outgoing email account one I am not even using? That was a riddle. The riddle was solved in the Mozilla Forums where they told me that if you used a google email smtp then "GMail has an anti-spoofing mechanism in place that replaces your sending address with your GMail address".

:o! Never again use Gmail SMTP in Thunderbird!