We are in the process of transitioning from 150 separate websites on individual domains to 150 domains all served by a central MVC app.
I am now wondering how to handle the MX record(s) on this new setup. I want the easiest way of setting the MX record to a third party mailserver for all 150 domains.
I'm pretty new to DNS so please go easy if I've got something wrong.
Domain / DNS Setup
The main app resides in a fake / unregistered, plesk-only domain.
The 150 live websites are registered active domains. In Plesk I have created them as aliases to the fake domain. The DNS of the aliases is set to by 'synced' with the fake domain.
Email is managed by a third party server.
I have tried adding an MX record
mail.thirdpartyserver.com on the fake domain, hoping the aliases would sync to this. But it doesn't seem to be working.
Is this because the domain from which the DNS is synced is fake?
Bonus question, possibly related...
There is an option for each alias labeled "Mail Service" (shot below). I don't know whether this should be off or on. I would "just try it", but because of the delay in DNS propogation, I'm finding it hard to assess the results of changes I make.