Need to be able to change Inquiry reply email

Hello, I have a question about the inquiry reply email. We currently do not like the wording and grammar, and would like to modify this email. To clarify, this is the email that is sent to a customer after a seller replies to their inquiry. We know our way around PHP somewhat well, but we cannot find the file where this email exists. If you could point us in the right direction, that would be great.

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