[iMore Question]

I have SENT an email and want to transfer it to DRAFT, to enable me to edit it on an Apple iPad

[Ledsteplin]

So you have already sent the email to someone and you want to put it in the Draft folder to edit before sending to someone else?
You can't drop an already sent email into Drafts. You can either start it as a new email from scratch, then drop it in Drafts or copy the sent email and paste it to a new one, then drop it in Drafts