Now that I think about it, I don't think I've ever seen an email verification flow that works in reverse, where the email owner sends the email instead. Seems it would be easy enough to say "Send an email from your indicated account with <pin> to <corporate email address>." I'm assuming the flow is different enough that it would lead to losing people who decide not to follow through but who would have continued with the 'normal' setup. It would also train users to send their MFA pins to others which would be a net negative for anyone using the normal verification process.