Delete mailbox behavior

1. Deleted mailbox can’t be restored

2. Mailbox will disappear from mailbox list at admin panel on mailbox page

3. If user tries to use deleted mailbox he will receive error 410 and will be redirected to first mailbox to which he has access. If user has no access to any of mailboxes he will be redirected to user profile page and all functionality will be blocked except profile and admin pages (if there is access to any account)