I'm in the process of migrating one of my domains from my SBS2011 to Exchange online plan 2. I made the changes to the DNS, MX records and disabled the SBS exchange mailboxes for the users involved and all seemed ok.
I setup two of the three users and I could receive and send email, though not from the rest of the SBS users, which I believe was an issue with the Global Distribution list not getting updated.
The main problem, which caused me to revert back to the SBS, is that one of the users had a free Microsoft account with the same email as the one that I was using for Exchange Online. This caused the email to be delivered to that account and not the correct one, as well as him not being able to see the other users of the Exchange online.
I changed the primary login of the free account but I couldn't get the account to work in Outlook and the webmail couldn't load either. Please see all my steps below and tell me if I am missing something. I already wasted a day on this simple process.
1) export emails from current SBS account
2) validate domain on Exchange online and make as primary
3) disable mailboxes on SBS so as to not have any conflicts
4) force update of Global distribution list (How?)
5) setup new accounts in new Outlook profiles and mobile devices
6) ensure internal and external mail flow
Can you think of anything that needs to be changed in the process above or can you elaborate with more details on certain steps?