550 Rejected from Cpanel Server

[bramvera]

hi all

newbie here, I just setup zimbra and running very good, tho i have to patch some glitch for ubuntu 7.10 amd64

I have server#1 with cpanel domainA.com
server#2 with with zimbra branch.domainA.com

communication from zimbra branch.domainA.com to domainA.com working very smooth

then we add new domain let's say domainB.com on server#2 running zimbra
communication to other mail server like gmail and yahoo are OK
but when we test sending mail to server#1 i've got immediate reply

This is the mail system at host  branch.domainA.com. 

I'm sorry to have to inform you that your message could not 
be delivered to one or more recipients. It's attached below. 

For further assistance, please send mail to postmaster. 

If you do so, please include this problem report. You can 
delete your own text from the attached returned message. 

                   The mail system 

<abraham@domainA.com>: host  domainA.com[ip xxx.xxx.xxx.xxx domainA] said: 
    550-Verification failed for <test@domainB.com> 550-No Such User Here 550 
    Sender verify failed (in reply to RCPT TO command)

FYI, on domainA server i modify exim to verify the sender, when I disable this, i can send the email fine from domainB.com but i don't want to disable this feature on exim

please any clue?
thanks in advance

[bramvera]

UPDATE:

i deleted the domainB and all users with zimbra Admin
then add domainB again
create the same user and test sending mail to Cpanel server is now working
no more 550 rejected, both with web-gui and mail client are fine

hmm weird, just wondering...

thanks all

[bramvera]

UPDATE:

i deleted the domainB and all users with zimbra Admin
then add domainB again
create the same user and test sending mail to Cpanel server is now working
no more 550 rejected, both with web-gui and mail client are fine

hmm weird, just wondering...

thanks all

oh no
happening again
can anyone help me please

[easytouch]

I see the same issue with sending from agmail account to
the latest FOSS 5 Version.

One time the error comes up 550 No Such User Here,
if I try it one minute later it works.

[jholder]

Try to grab as many logs as you can from the time that it happens.

[bramvera]

i just drop off zimbra, i thought no one gonna answer it
will try later when our company decide to use zimbra commercial or not

thanks anyway

[easytouch]

For me the issue is solved, because it was a typo in the DNS-Zone records.

It was so hard to find, because Gmail does not give you the IP address of your server which throws the 550 error message.

It was found now as we had the 550 message from gmx.net which gives you the IP in the error message.

Four things we learned.

1. The above 550 error was not a ZImbra issue (for us).
2. Tests from external should be done from ISPs delivering the minimum needed content for error messages
3. Collect all your logs from all your servers in one central location to save time.
4. Double and Tripple check all configuration settings (from DNS-Zone to Zimbra and Postfix configs)