[SOLVED] Problems with DNS (on CentOS5 and Zimbra5 RC2)

[xaosmail]

Hello @all,

i have installed zimbra on a xen virtual machine, using debian etch for dom0 and centos5 for domX. Everything fine, except the main feature -> I can't send or receive mails.
First of all, I have read nearly the whole wiki and the forums for dns questions..nevertheless I have no solution for my problem.

Symptoms: Send/Receive Mail doesn't work (even inside mails)
Caution: all < and > replaced with ### due the fact that the forum software doesn't display this in code mode

Dec 20 13:37:03 mail postfix/smtpd[13007]: A42F08C1A8: client=unknown[195.122.130.23]
Dec 20 13:37:03 mail postfix/cleanup[13012]: A42F08C1A8: message-id=###1198157055.5859.14.camel@dontcare###
Dec 20 13:37:03 mail postfix/qmgr[9718]: A42F08C1A8: from=###test@externaldomain.de###, size=2349, nrcpt=1 (queue active)
Dec 20 13:37:03 mail amavis[9614]: (09614-01) ESMTP::10024 /opt/zimbra/amavisd/tmp/amavis-20071220T133703-09614: ###test@externaldomain.de### -### ###test@dissz.net### SIZE=2349 BODY=8BITMIME
 Received: from mail.dissz.net ([127.0.0.1]) by localhost (mail.dissz.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP for ###test@dissz.net###; Thu, 20 Dec 2007 13:37:03 +0000
(UTC)
Dec 20 13:37:03 mail postfix/smtpd[13007]: disconnect from unknown[195.122.130.23]
Dec 20 13:37:03 mail amavis[9614]: (09614-01) Checking: p8oIhaurAHTf [195.122.130.23] ###test@externaldomain.de### -### ###test@dissz.net###
Dec 20 13:37:04 mail postfix/smtpd[13016]: connect from localhost.localdomain[127.0.0.1]
Dec 20 13:37:04 mail postfix/smtpd[13016]: 18DCF8C1A9: client=localhost.localdomain[127.0.0.1]
Dec 20 13:37:04 mail postfix/cleanup[13012]: 18DCF8C1A9: message-id=###1198157055.5859.14.camel@dontcare###
Dec 20 13:37:04 mail postfix/qmgr[9718]: 18DCF8C1A9: from=###test@externaldomain.de###, size=2907, nrcpt=1 (queue active)
Dec 20 13:37:04 mail postfix/smtpd[13016]: disconnect from localhost.localdomain[127.0.0.1]
Dec 20 13:37:04 mail amavis[9614]: (09614-01) FWD via SMTP: ###test@externaldomain.de### -### ###test@dissz.net###,BODY=8BITMIME 250 2.6.0 Ok, id=09614-01, from MTA([127.0.0.1]:10025): 250 2.
0.0 Ok: queued as 18DCF8C1A9
Dec 20 13:37:04 mail amavis[9614]: (09614-01) Passed CLEAN, [195.122.130.23] [195.122.130.2] ###test@externaldomain.de### -### ###test@dissz.net###, Message-ID: ###1198157055.5859.14.camel@dont
care###, mail_id: p8oIhaurAHTf, Hits: 3.667, size: 2348, queued_as: 18DCF8C1A9, 349 ms
Dec 20 13:37:04 mail postfix/smtp[13013]: A42F08C1A8: to=###test@dissz.net###, relay=127.0.0.1[127.0.0.1]:10024, delay=0.54, delays=0.18/0.01/0.01/0.34, dsn=2.0.0, status=sent (250 2
.0.0 Ok: queued as 18DCF8C1A9)
Dec 20 13:37:04 mail postfix/qmgr[9718]: A42F08C1A8: removed
Dec 20 13:37:04 mail postfix/lmtp[13017]: 18DCF8C1A9: to=###test@dissz.net###, relay=none, delay=0.02, delays=0.01/0.01/0/0, dsn=4.4.3, status=deferred (Host or domain name not found
. Name service error for name=mail.dissz.net type=A: Host not found, try again)

Postfix has Problems with DNS, ok..

my /etc/hosts, but afaik postfix doesn't use this

127.0.0.1 localhost.localdomain localhost
78.47.207.92 mail.dissz.net mail

DNS seems right, even rdns seems correct

dns check for dissz.net (mx) and mail.dissz.net (a)
host -t mx dissz.net
dissz.net mail is handled by 10 mail.dissz.net.
host -t a mail.dissz.net
mail.dissz.net has address 78.47.207.92
host 78.47.207.92
92.207.47.78.in-addr.arpa domain name pointer mail.dissz.net.

No ideas left, can somebody help me?

xaos

EDIT: The CentOS Xen machine has its own IP and is connected via XENBR (Xen Bridge) to the net. Direct Connect via http to Zimbra Collaboration Suite Log In works, Webfrontend works like a charm

[phoenix]

Is SELinux disabled? It should be. If you are behind a firewall you may also need a Split DNS or you may need to open some ports.

[xaosmail]

W00t! Failure found..

Two Issues:

a) selinux was enabled
b) /etc/resolv.conf had incorrect permissions (user postfix couldn't read them)

thx for the help

xaos