0
Currently we are running on an older mail service where each client uses IMAP and SMTP to connect for incoming and outgoing mail. This is not Exchanged-based - let's call it "old school" mail server with little options for configuration. It doesn't support more modern push services for mobile devices, and its SPAM filtering and mailbox filtering is poor or non-existent.
I would like to setup a more modern mail server and slowly move my users over to it. This might be Google Apps for Business, but it might also be Office365, we haven't decided yet. In any case we want to move to a service where we have more fine-grained administrative control over SPAM rules, and also server-side filtering and mailbox rules (right now everything is client-side).
How would I go about "splitting" incoming email - so some of it continues to deliver to the old system and those users can continue to use that system unaffected, and the users I move over can have email delivered into their newer, more modern email server?
AFAIK there is only one set of MX records, and none of them delineate anything about users, but it's been quite some time since I setup email services so I may be out of date and/or missing something.
If the "old school" mail server supports forwarding rules, it can forward some mail to the new server, until it is totally replaced. At worst, you may set up a frontal server that will split the mails. – harrymc – 2019-10-17T14:54:28.897
Can you elaborate on this "frontal server" concept? – jimmy0x52 – 2019-10-17T15:25:04.497
Presumably it's just a third server that acts as your MX and only forwards mail to either the old service or to the new one. – user1686 – 2019-10-17T15:44:10.590