I have setup an Ubuntu 12.0.4 server to host my websites using Apache virtual hosts. I want to use Zimbra for mail (and later, group collaboration).
I have the following sites being hosted by the server:
I want to be able to allow users to access mail on each site by simply going to the respective mail address and providing the relevant credentials:
Note: Each of these websites are for separate entities (businesses), so I want each of the mail address to require the user to be prompted for username/pwd to login.
Last but not the least, I wonder how secure having a "public" interface to mail is, i.e. is it sensible to have mail.sitename.com globally exposed to the world (it seems like it would tempt hackers) - is there any way to secure this (example lock out after N unsuccessful login attempts?)