[Dovecot] Lock down Shared Mail Accounts?

[Ed W]

> I want to give multiple people shared access to some actual accounts 
> with all of the special use folders, with the following requirements:

I have done this (unsatisfactorarily) by making it a normal mail account 
with normal login credentials.  Add it like any other mail account.  It 
then satisfies all your requirements, although: behind a nat, on 
thunderbird and with condstore, I sometimes see read/unread get out of 
sync... Believed to be a thunderbird bug, but unsure. Easy to resync


> 5. No one other than a designated user or users (Master User(s)? Users 
> in a specified Group?) can delete any messages in this account, in any 
> of the folders.

Have them delivered with only read permissions on the physical files? 
(Bet that doesn't work very well in practice or other than maildir...)

Interested to hear proper answers...

Ed W