Hy,
it would be nice if the answer email to "Email to requester" would have more information.
"To add a comment, reply to this email. The enquiry number is 123456789" is very less information if some lost the original first email with the summary. Externals have no possibility to check the tickets. So it would be nice to have the ticket information in the answer and / or the communication history like the last 3 comments or something like this.
Best regards, Tobi