After a new message has been created but not yet sent, you can save a copy (draft) to edit or send later.
To save a Draft:
Click the ellipsis icon and choose the Save option to save a Draft of the message.
To edit a saved Draft:
Click on the Drafts folder and select the message you would like to continue editing.
NOTE: Drafts will be named by what was entered in the Subject field and by the recipient list.
TIP: A Draft is periodically auto-saved. You can check the last time a Draft was saved by the time stamp indicated above the To... field.