Blog Post

Outlook Blog
7 MIN READ

Enhanced performance, designed for simplicity – the new Outlook for Mac

Jessica_Wilczek's avatar
Jessica_Wilczek
Icon for Microsoft rankMicrosoft
Sep 22, 2020
A year ago, we introduced a preview of the new Outlook for Mac to our Insiders. Since then, we have been hard at work enhancing the experience, and have developed a product that is designed for you. ...
Updated Nov 20, 2020
Version 3.0
Outlook for Mac
fymayawf's avatar
fymayawf
Copper Contributor
Aug 28, 2025

We expect that Outlook for Mac “legacy” can still be used. The integration of delegated mailboxes does not work at all, even with full access. We are simply annoyed by the new version and expect more professionalism. The current version is really unusable.

Outlook for Mac – Known Issues (Version 16.100 / 16.100.1)

Shared Mailbox – Add via Delegation

Steps: Settings > Accounts > YOUR ACCOUNT > Delegates and Sharing > Shared With Me > + or File > Open > Shared Mailbox
Issue: After selecting the mailbox → "Checking Permissions...", repeated credential prompt, then error "Cannot open this mailbox. Unable to sign in. Try again or create an app password for this account."

Shared Mailbox – Add via Personal Credentials (Full Access)

Steps: Settings > Accounts > Add Account > Enter shared mailbox address > Select Exchange > Use personal credentials
Issue: Mailbox seems to map, but in reality only the personal account is added again. Sent emails appear with the personal sender, not the shared mailbox (nor “on behalf of”).