I have been working away at this to find a simplified way to change over email addresses during migration, it has taken lots of time to get to today.
So I found a way today to change email addresses very quickly for shared mailbox scenario’s.
First of all you need to connect to Exchange Online. (https://technet.microsoft.com/en-us/library/jj984289(v=exchg.160).aspx)
These commands need the connect-msonline
Note also some very good instructions also at Docs.com
Now the next part changes the UPN, this is exactly the same as doing it on-premise AD (as per my previous post ) .
Set-MsolUserPrincipalName -UserPrincipalName “email@example.com” -NewUserPrincipalName “firstname.lastname@example.org”
This sets the UPN and email address up for you! Nice!
The next step is to set the default reply address
Set-Mailbox email@example.com -WindowsEmailAddress firstname.lastname@example.org
Job done ! Easy !