Here’s a way to get your drafts folder back. Note that all previous saved mails are lost.
- open photo app
- select a photo
- click the small icon on bottom left to forward your photo to another app
- select mail app
- do not send the mail, click ‚cancel‘ instead
- click ‚save draft‘
- kill mail app
- start mail app
- your draft folder is back and you can save normal mails again