Can I change the ticket requester within Zendesk based on the contents of the email body?

Question

How can I set the requester of an email ticket to reflect the user information shown in the body of a ticket created through email? 

Answer 

The email body is not used in any way to identify the requester of a ticket. Zendesk uses information from the email headers to determine the ticket requester. The primary way a requester is set is by the reply-to: header flag. If the reply-to: header is not present, from: is used in its place. This functionality is hard-coded into the system and unchangeable.

However, agents can use mail API #requester syntax to set the requester on a ticket. For more information, see the article: Using the Mail API to update ticket properties from your inbox.

For more information on email threading, see the article: How can I troubleshoot threading issues?