How to setup Shared Mailboxes - with Modern Authentication

[Martijn]

Hi,

Need some guidance on setup the shared mailbox with modern auth. 
i have setup a KeySafe password with the username that currently connects to that mailbox.
Sharedmailbox: isteam-nl@domain.com
Sharedmailbox Account: GenITSM-Email

I'm able to setup the shared mailbox and send email out but not receive any email. 

Looking at the ESPMailIMported log. 
ImapCmdResp: aaac BAD User is authenticated but not connected.

how can i fix this?

/martijn

 

[Martijn]

Anyone got a idea? 
Wanted to disable normal login asap and only use oauth2.