There have been cases where a buyer demands a seller’s email. But because Fiverr doesn’t allow this, the Seller ends up losing the job.
I want to make a suggestion: Fiverr can ask their programmers to assign automatic email to every seller using their username. For instance; your Fiverr email will be firstname.lastname@example.org.
A buyer can send message to such email and it will land on the seller’s inbox inside Fiverr. I think this will improve conversion for most of us.