I know very basic linux/dns knowledge, so please bear with me.
Zimbra is up and running on Red Hat EL. I didn't have access to change mail.companyname.com to point to the new Zimbra server. When I went to send a test email I got the following ...
To get rid of that I changed 'disable_dns_lookups' to 'yes'. Mail inbound, has no problems now.This is the Postfix program at host mail.companyname.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 Postfix program
'user1@companyname': Host or domain name not found. Name
service error for name=mail.companyname.com type=A: Host not found
Final-Recipient: rfc822; email@example.com
Diagnostic-Code: X-Postfix; Host or domain name not found. Name service error
for name=mail.companyname type=A: Host not found
Outbound mail however does not work (both web client / mapi connection). I can authenticate fine, it even acts like it sends the email, not bounces etc. The mail never gets out though.
Please point me in the right direction to troubleshoot outbound email. Let me know if I need to provide any other info (I am using eval ZCS downloaded it 2 days ago, 3.2.1 or something).