For my image import profile, we want to access a shared mailbox (testmailbox) using a service account (testaccount).
We are using an IMAP server with the source: firstname.lastname@example.org.
The settings are using email@example.com as the login.
We can browse the testmailbox but cannot access testaccount.
Error: The mailbox 'firstname.lastname@example.org' was not found on IMAP server.
In the source field, you need to enter the IMAP server and mail folder.
Try the following
login: (user\shared mailbox) email@example.com\firstname.lastname@example.org