I use Virtualmin at host.domain.com, and I host several websites on virtual servers.
I want to install Rainloop to be used at mail.domain.com, so I can send/receive emails for all the domains from there. I also want the emails to be secured with SSL, and pass all DKIM etc security tests.
What’s the best way to do this, and is it possible for me to use mail.domain.com, or do I need to use mail.host.domain.com, because that’s where Virtualmin is installed?
I think it was written in the documentation tow to use a global mail domain.
If you want to use rainloop, simply install that script on one of the servers and enable SSL in that server (server configuration -> SSL certificate).
You could also use the usermin mail system.
If I recall it correctly, its like your first example.
If you set it up according to the documentation, it should work with sending and receiving messages.
I have rainloop on rainloop.indiax.com and it serves users on vps01.indiax.com, vps02.indiax.com and so on. Rainloop can be configured to serve whitelisted domains regardless of where they are hosted - be they on your Virtualmin server or on any other IMAP server elsewhere on the net.