Save a draft in Mail on iPhone
In the Mail app , you can save a draft to finish later, or look at existing emails while you’re writing a new one.
Save a draft for later
If you’re writing an email and want to finish it later, tap Cancel, then tap Save Draft.
To resume work on an email you saved as a draft, touch and hold , then select a draft.
You can also swipe down on the title bar of an email you’re writing to save it for later. When you’re ready to return to your email, tap its title at the bottom of the screen.
Tip: If you have a Mac with OS X 10.10 or later, you can also hand off unfinished emails between your iPhone and your Mac. See Hand off tasks between iPhone and your other devices.
Show draft emails from all your accounts
If you have more than one email account, you can show draft emails from all your accounts.
Tap
in the upper-left corner until your see Mailboxes.
Tap Edit at the top of the list.
Tap Add Mailbox, then turn on the All Drafts mailbox.