I spent an hour messing around with getting this working, as it never occurred to me that the seemingly basic functionality of having an Action Rule send an email to a client (by putting the tag <client_email> in the "Recipients" field would not be a thing. Turns out that it is not a thing. This makes me sad as I am creating some ticket types for our IT department and wish to send an email to the client with directions when the ticket is closed by a tech. It does work if a specific email address is put in.
My workaround is to update the ticket with a note when it's closed. Yeah.. that works. but a nicely formatted email popping into the client's inbox would be so slick. Plus I see a thread where someone requested this feature over 7 years ago. It'd be super if this was implemented.
Cheers,
Dave