What do you call someone who makes a request?
Solution 1:
I would go with "requestor" because they are making a request.
Other phrases used for similar concepts in some of the various software tools installed on my workstation: "originator" (but it applies generally, in a system that has more than just "requests"), "creator", "initiator".
Solution 2:
If you are not limited in space, you could use
Do you really want to send an email to the person who made the request?
Otherwise, requester is an acceptable English word to express this same thing.
Solution 3:
For this context, might you be able to get away with user, customer, or client?
Solution 4:
Depending on your context, you can use Requester or Requestor
Solution 5:
In diplomatic terms, the word is a demandeur.