Since Zoho CRM does not offer the possibility of a shared e-mail inbox (i absolutely couldn't believe that, but a shared IMAP is simply not supported.... PLEASE change that!), we have to use the helpdesk as a detour.

Our company has a simple info@.... address for customer contact.

Since it is not possible to make this info@...accessible via IMAP for all of our ZOHO users, we now have to forward all emails from info@... to the helpdesk support email address, so that we have a "shared mailbox" there...

Anyway, in the helpdesk all new tickets are not initially assigned to an agent and I would like to create a direct assignement rule according to the following logic:

If the ticket is not assigned to anybody it should be assigned to the first agent who opens it.  To make it clear: Its NOT about assigning the ticket to an agent when he answered it, but when he open it. 

When creating this workflow I fail first of all because of the criterion "on opening" (I don't think so)

and second, when assigning "to the appropriate user" (there is no such thing, there are only specific users that can be selected there)

Can you give me a tip on how I can reach the goal of "assign tickets to the person who opens them first" in another way?