Historically, Exchange has used a user’s primary SMTP address as the From address when sending messages. Other SMTP addresses assigned to a user (e.g., proxy addresses, also known as aliases) were ma...
Updated Oct 21, 2024
Version 11.0
Blog Post
Can anyone advise with respect to support for this feature for Windows Mail?
I am running Windows 11 Pro 22H2 with all updates applied, and Windows Mail Version 16005.14326.20970.0 (latest). I am using it with my Microsoft 365 E5 account. I have this feature enabled and have several aliases on the account.
Up until a few months ago, Windows Mail did not recognize the aliases, and only allowed me to send from the account's primary email address. More recently, presumably with a recent update somewhere, the behavior is reversed. Now, I can no longer send from the account's primary address, and can only send from the aliases. When composing a new email on the account, I am offered every alias on the account as a From: option... except the primary/default address itself. I even now see the legacy "onmicrosoft.com" alias being offered. But I can no longer send email as the primary address on my Microsoft 365 account from Windows mail.
The send as alias functionality works perfectly everywhere else: 365/OWA, Outlook 365, Outlook mobile, etc. Only Windows Mail is having the problem. Furthermore, the functionality is only broken on the business-level 365 accounts: Windows Mail has no problem sending from the primary and aliases on my personal "outlook.com"/live.com accounts. For those accounts, the From: menu does display the primary and all aliases, and it always has. Only the interaction between Windows Mail as a client, and Microsoft 365 (business) as an account, exhibits this problem.
I note that Windows Mail is not listed on the original post as a supported client. Seems to me that it should be supported, since it's a Microsoft app. But, at a minimum, if it's not supported, I suggest that it should ignore the setting and offer the primary address, instead of offering only the aliases. But Windows Mail fails to display the primary address as a From: option when sending from a Microsoft 365 account with a business or enterprise license.
Things I've tried: Resetting Windows Mail, Removing the identities, removing and re-adding the account, uninstalling Windows Mail and resinstalling. I have several computers, and they all exhibit this behavior, leading me to believe this is a protocol issue. Moreover, if I disable the "send as aliases" functionality in my tenant, Windows Mail (after 24 hours) goes back to the correct behavior; but then of course I cannot send as aliases using any method, so that's not really an acceptable outcome either. Any insight would be welcome!