The View Recipients (N) link under the selector shows how many unique people will receive the message. The count updates every time you change the selection. Click the link to open the Recipients List, which shows each recipient’s display name and email address, and — for clients — the technician(s) they are assigned to. Click the trash icon next to any recipient to drop them from this send only; this does not change the client record.
Note: As the list itself says, only clients with a valid email are included. A client with no email address is skipped even if they belong to a selected group, and does not count toward the total. A client whose email field holds several addresses separated by commas is emailed at each address.