email work for gmail and hotmail but not for regular email

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