It's weird, and I remember other people talking about it on here earlier. In the document it says to send documents to the Mexico VO address, but in their actual email it says:
"You can submit this information via e-mail, it is not necessary to send these documents on paper to our office in Mexico.
***Please do not modify the subject of this email when you submit the requested documents, simply reply to this message.***
E-mail:
mexico-im-enquiry@international.gc.ca
* Please include your file number, complete name and date of birth in all your enquiries."
For now, I'm sending the photocopy but in the email I'll ask if they need the physical copy, and then send that as well if they do.