We successfully completed a cut-over migration from Exchange 2010 to O365. We utilized the Azure AD Sync Tool to populate all the users and sync all the mail. The migration actually completed the first week of January. I've left the exchange server up and running just in case something went wrong this whole time.
On February 3rd, I disabled the Azure AD sync with O365, so now all mailboxes Sync Status shows the "Cloud" instead of "Sync with AD". I left the Azure AD Connect Tool installed on one of our DC, and will remove it in the near future.
On February 6th, I powered down our Exchange 2010 server and then powered it back up yesterday, February 13th. I just wanted to make sure any mail related services were not pointing to the Exchange 2010 server. One week with the server off-line should be sufficient for this need.
Now I want to start removing the Exchange 2010 completely. All O365 mailbox management will be done in the O365 console. and I simply do not want to have any exchange services within our local network. I want to properly remove the exchange server so that all the Exchange AD attributes are properly removed in case we decide to install another on-prem exchange server in the future.
I first want to know if I need to remove all the mailboxes before removing mailbox databases, etc. I am using the following article to assist me remove Exchange:
I tried deleting my mailbox within the Exchange 2010 console, by right clicking on my mailbox located within Recipient Group\Mailbox, and selected Remove. However, after completing this task it actually deleted my AD User Profile of which I did not want, and also placed the mailbox within Disconnected Mailbox container\folder. I was able to restore my AD User Account, and my mailbox reappeared in the Recipient Configuration\Mailbox list, but I have not been able to reconnect the disconnected mailbox since my user account does not appear in the list of existing users. Not sure it matters at this point, but I want to make sure I do not have any issues properly removing Exchange.
I need to know if its necessary to delete all the exchange mailboxes before removing exchange databases, etc.
If so, how can I remove each mailbox without deleting the associated AD user account.
Finally, I want to know if the above link used as reference to remove exchange 2010 is recommended for my need or not. I want to remove everything before going to add/remove programs and features, and actually removing Microsoft Exchange 2010 Standard.