Sending mail on OS X

[Someone Dechezmoi]

Hi
Initially congratulation for the Tor project. It's very fantastic.
Sorry for my small english... I'll try to explain my question.
It is possible to torify PostFix on OS X... PostFix is an SMTP server  
on Tiger.
So Tor works very well with Firefox... but when I send a mail with  
Thunderbird... the mail don't come. If I try to send a mail to myself  
it works but I have my personnal IP. When I send a mail on webmail  
adresse... like Yahoo... the mail is not arrived.
If you can help me it will be cool.
Regards.
I invite French guys to answer in French... is it's possible.
Thank You all