Queue filling up with NDRs

[b27520]

I have a zimbra server relaying through exchange (required for our firewall setup, network admin didn't want to add a rule since we are trying out zimbra first)

So the Exchange queue is filling up with all the NDRs from the zimbra server, basically says it can't connect to the domain to send the ndr.

In Exchange I can turn on reverse DNS to verify the domain before accepting the message. Is there anything like this in Zimbra that way it never accepts the message, because oviously the domain doesn't exist because it can't connect to send the NDR.

Any ideas?

[LMStone]

Here's the definitive guide IMHO for dealing with backscatter:

Postfix Backscatter Howto

Hope that helps,
Mark

[b27520]

Where are the postfix files in zimbra, the link says to look in /etc/postfix but this doens't exist. Since I use zimbra I'm sure it is somewhere else.

Also I have postfix 2.4.7, so this should be on by default right?

If not where do I find the files in zimbra to make the changes?

[LMStone]

Originally Posted by b27520

Where are the postfix files in zimbra, the link says to look in /etc/postfix but this doens't exist. Since I use zimbra I'm sure it is somewhere else.

Also I have postfix 2.4.7, so this should be on by default right?

If not where do I find the files in zimbra to make the changes?

The postfix files are in /opt/zimbra/postfix. Everything (well, almost everything...) Zimbra is in /opt/zimbra.

I didn't mean for you to start hacking Zimbra's Postfix files right out of the box; I'd be surprised if that is really necessary.

The document describes how typical misconfigurations create backscatter emails, and how you can avoid them. My sense is that the misconfigurations in your case are elsewhere other than Zimbra's Postfix configuration files, so I thought that document would help you in the first instance get a better understanding of the whole backscatter issue and then take steps to eliminate the root cause of the backscatter in your network environment. In that regard, editing Zimbra's Postfix config files is probably the last thing you will want to do, if you even need to do it at all.

Hope that helps,
Mark

[b27520]

I found the file it turns out reject_unlisted_recipient was set to no, so I change it to yes. This resolved alot of my issues, now I just have an issue with full mailboxes sending over quota messages to server that don't exist.