is is able to setting up DNS server reverse lookup with DynamicIP?

[Olivier Nicole]

> But my postfix only can receive mails from freebsd-questions mailing
> list, it can not send mail to this. 

There is another thing you have to consider. As it is explained in
http://www.bsdforums.org/forums/showthread.php?p=265093#post265093
your dynamic IP has been black listed (the IP was used before by
someone else who sent SPAM, so now the IP is in a list of bad guys and
many mail server will refuse to receive emails from your IP).

So it is really a better idea that you sent all your email thought FPT
email server.

Best regards,

Olivier