@syko24 said in MS Teams file attachments and changing primary email address:

So the only way I see you can fix this is to login to the AzureAD portal and change the UPN to the original email address and then make sure the primary email address is the new updated email address. The downside is that when you want to sign into Teams, Outlook, etc. you have to use the original email address that matches the UPN even though your primary email address is different. mcdvoice

Many thanks for that complete information!