Make a Open Relay ONLY for my IP subnets

[mustu]

Hi,
We have implemented a policy in our network to force users who aren't using our smtp account to go though our relay server to pass email of another smtp. Our IPs were frequently getting blocked in DNSBL lists due to heavy spamming so, we need to stop our users from connecting any smtp and send millions of SPAM. If they aren't hapy to use our company's smtp account and want to use their own smtp then they have to relay the email from our relay server so we can discard SPAM actions and help imrpove our PUBLIC IPs reputation on web.

Refer me to any manual on how to
* Restrict Zimbra to accept sending message from ONLY my defined IP subnet.
* Let anyone from my subnet relay a message without any authentication.
* Define custom spam rules.

[phoenix]

Originally Posted by mustu

Refer me to any manual on how to
* Restrict Zimbra to accept sending message from ONLY my defined IP subnet.
* Let anyone from my subnet relay a message without any authentication.

Those are the defaults of a Zimbra server, only authenticated users may relay mail through the server and LAN users don't need to authenticate. If you're having problems with getting blacklisted because your users are sending spam then you probably have other security problems.

Originally Posted by mustu

* Define custom spam rules.

Search the wiki and/or forums for details on how to improve the anti-spam system, there's plenty of threads and articles on the subject.

[mustu]

We are kind of sub-ISP and our customers do use Public IPs. They do use or mostly virus/spyware on their computer do connect with relaying server on web and send SPAM and our those Public IPs get listed in DNSBL lists.

We are blocking smtp for all except the one we verify. We want everyone else to go through our open relay so we can put a check on the traffic and stop the spam.

I hope you it clarified my concern. Kindly let me know if it doesn't.