[SOLVED] sending e-mails between my zimbra domains

I have more than 30 domains in my Zimbra Mail Server. They are working good with sending/receving mails from outside. But when i try to send e-mail between my zimbra domains, e-mails are going to junk folders at microsoft outlook. So the problem is sending e-mails between my zimbra domains. They are falling in junk mail folders. Does anyone have the same situation? Do you have any suggestion?

Check /var/log/zimbra.log to see why they are being tagged as SPAM. If they are passing clean then it will be Outlook that is intercepting them.

ok, well noted. will check and type here the progress.
Thanks.

@uxbod,
I figured out that with checking /var/log/zimbra.log
It was because of the missconfiguration on my dns zone.
Thanks for your help.