All tickets not shown

I'm testing Zoho desk so maybe I've set something up incorrectly since I'm new to this system.

I've set up 3 email accounts - each one linked to a separate department (including the default).

When I pretend to be a customer and send emails to zoho desk from various email accounts not all of them show up in the all tickets screen.

I have sent 5 tickets from 3 accounts - only the first 3 tickets appear in the all tickets screen.

When I accept the registration as a customer I can see my 3 tickets there but I can't see them on the home page with all tickets.

Why aren't all the tickets appearing on the all ticket screen?

I have synched with contacts in Zoho CRM and those emails won't exist there. Is that something to do with it?

Thanks for your help,
Karen