Mr Russell wrote:
When they turn up for their appointments I hope the shop will tell them.
Them: Hi, yes, I'm here for my appointment. My name's Mr. Russell.
Dentist: Sorry, we don't have any appointments under that name today. What time was your appointment?
Them: 2.30.
Dentist: Hmm, no, sorry, that's an appointment for a Mr. Email-Address.