IMAP login to a shared mailbox

When using telnet for imap you can write:
? login domain-abc/user-123/mailbox-456 pword
this way you can with a service account access another group/persons mailbox with the correct rights offcause.
But I can't make it to work for the IMAP setup in JIRA. If I write domain-abc/user-123/mailbox-456 in the username field i get an error when testing (authentication failed).
Can the IMAP JIRA implementation access a shared mailbox? and how to config?

Workaround courtesy of david.dixon:

A3 BAD User is authenticated but not connected error message when using JIRA with Office365