How to deny SMTP relay
I am setting up a Zimbra 5.0 server for my campus. I want all users to use the web interface to access the mail server. Can I configure the server so that it does not allow anyone to use any mail clients like Outlook, Thunderbird, Mac, Entourage, etc ?
If so, is it possible to selectively allow relay for some users and deny relay for all others ?
QMail has a setting wherein, we can deny relay for users by checking a check box in the setup.
Within the Admin GUI under the MTA tab it will have your network settings. If that has just 127.0.0.1 then nobody will be allowed to relay though your server.
If you are able to identify which computers you will allow to relay, perhaps by having two seperate DHCP pools or reservations, then you could selectively allow only certain nodes to relay.
This means that I cannot selectively specify the hosts for whom I want to relay. I can only specify a network (?)
Will it work if I use iptables to block all smtp connections from all hosts and allow SMTP connections only to those whom I allow use of Outlook, Entourage, etc ? Will this create any problem for Zimbra SMTP ?