i have setup postfix in my linode following linode library it work when i send mail to gmail ,hotmail ,yahoo but not for regular email whom is working when i send to them from gmail

does any one have any idea what the problem can be ?

When I used sendmail, it wrote errors to /var/log/maillog. Maybe postfix does something like that?

Dec 4 11:14:54 ubuntu postfix/smtp[7917]: D4124101D0: to=<yassine.ezzine@servi.com.tn>, relay=mx2topnet.ingw.tn[193.95.97.67]:25, delay=8990, delays=8985/2.9/1.6/0.69, dsn=4.0.0, status=deferred (host mx2topnet.ingw.tn[193.95.97.67] said: 451 #4.1.8 Domain of sender address <www-data@ubuntu.dev-station.com> does not resolve (in reply to MAIL FROM command))

this is the error in log file

how to fix this

It cannot resolve the domain

ubuntu.dev-station.com

Are you sure the A/CNAME Record is active? It won't accept mail because it cannot resolve that domain, and neither can I.

This must be the root of your problem.

this is the old domaine name
what to do chnage it

I'm going to guess that's the server name. In CentOS, you'd change it in /etc/sysconfig/network and reboot.

i found it in
/etc/mailname
now everything works fine
thanks any away