Everyone from the same requestors email-domain should be able to reply to a ticket?

Good evening everybody,

We set the global rights for “Requestor” and “CC” to reply to a ticket.

Because we are using RT3 in the B2B environment, we often faced to the
situation, the another
employee from the some company than the requestor (therefore, with the
same email-domain)
reply additionally to this ticket. Of course, this email will not
recorded because of lack
of permissions.

I would not like to set the global right “Everyone is allowed to reply”!

Question: Is there a way to allow senders from the SAME email-domain
like the Requestor to reply to a ticket ?

Kind regards