Mailbox Limitations

Hi GLA365,

There are a few options here

1.) You would purchase mailboxes and licences and move them over. They don't need to be full Office 365 licences, if it's only mailboxes they use you could use Exchange Online Plan 1 licences which are cheap. Or even cheaper is Kiosk mailboxes which are online only and have a 2Gb limit.

2.) If they are not having mailboxes going forward and using their own mailboxes then you would simply use mail contacts to forward onto these mailboxes

3.) If you leave the mailboxes on the old server you can use a send connector in Exchange Online and set the domain to non-authoritative to relay mail to the old server. On the other end (the old end) forward the old mailboxes to the new mailboxes (the onmicrosoft address not the main domain). The issue here is that you would put the systems into a form of coexistence meaning added overhead, split address books, and not being able to shut down the old platform (which I am guessing is the point).

This situation often occurs where organisations have something like a very old exchange server, a linux platform or imap platform not previously paid for. It is generally recommended to get them onto Exchange Online/365 and then charge the partners/consultants for the mailboxes. This is for several reasons including better security (I.e. implementing MFA), unified address book, data compliance, modern aligned apps etc.

Hope that answers your questions!

Best, Chris