Office 365 / 2 Form Authentication / App Password / Shared - Microsoft Community

we have user accounts have 2 form authentication enabled on them, have app password outlook access , run in exchange cache mode. attempting add account shared mailbox. can go through process of adding shared mailbox , prompts password, use app password, , accepts , adds it. nit tells me have re-load outlook changes take affect. restart outlook , hangs @ preparing outlook first time use. 

note: adding account through file > add account rather going account settings , opening additional mailboxes. way because want make shared mailbox default mailbox , send emails account default.

eventually cancel outlook "preparing first time use" , when start outlook again, opens cannot access shared mailbox. says cannot expand folders.

thanks 

hi damianjht,

firstly, please noted users can’t log shared mailbox directly using outlook doesn’t have own user name or password. must first assign permissions (the full access permission) user access shared mailbox, , can access using outlook. , it’s same case when multi-factor authentication enabled on user’s account. more details, please refer article:
https://support.office.com/en-us/article/create-shared-mailboxes-in-office-365-871a246d-3acd-4bba-948e-5de8be0544c9

moreover, here 2 recommended methods access shared mailbox in outlook client:
1. grant full access permission of shared mailboxes , let them appear automatically via automapping.
2. or grant full access permission of shared mailboxes , remove automapping shared mailbox, add them manually additional mailboxes (in file> account settings> double-click account> more settings> advanced> add) in outlook client.

can refer either 1 , let know how works. let me know if unclear.

regards,
sam

Office / Outlook / Windows 10 / Office 365 for business