Fresh Zimbra install is an open relay

[paul]

I've just completed a Zimbra Open Source install.
At the end of it, I ran some checks, and it seems that the server is an open relay.
I tested this using the following online checks:

• mxtoolbox.com
• https://www.dnsexit.com/Direct.sv?cmd=testMailServer),

both of these reported the server was an open relay.

I also tested using the "sendemail" script from a different ubuntu box.

Code: Select all

sendemail -f "does.not.exist@mydomain.com" -t "emailaddress@someotherdomain" -u "relay test" -s "mydomain.com"

This happily sent an email to "emailaddress@someotherdomain", from the non existent email on my domain.

I read in the documentation that zimbra's postfix is supposed to have open relaying turned off by default.
Have I turned it on by mistake? How do I turn it off?

Many thanks.
Paul

[phoenix]

Zimbra, by default, is not an open relay and would only be so if you've made any changes to it. What changes have you made? Have a look at some of the other questions/solutions on the forums for details of what you can check.

[buruguduy]

Have you checked ZimbraMtaMyNetworks? It should provide you with knowledge of how to configure which network or host will be allowed to send. I have found this since version 8.0.

[paul]

Zimbra, by default, is not an open relay and would only be so if you've made any changes to it. What changes have you made? Have a look at some of the other questions/solutions on the forums for details of what you can check.

While I didn't think I had done anything to enable open relay... I have since
run through a couple of "how to harden zimbra" websites,
and the open relay seems to have gone away.

It is very possible that I messed up during installation.