Display email count for partially delegated inbox(es)

Currently, there is no email counter for delegated inboxes.
I am proposing that delegated inbox should have counters, just like all other inboxes.

Just like in any other inbox, email count is necessary (and expected) so you can know when you have new emails, how many emails you have, etc..
Without a count of emails it is difficult to keep up and achieve the coveted inbox zero- if there is no count at all.