When composing any email, we may get distracted and want to send the email later. You do not need to lose the draft message, you can save it in Gmail.
And Gmail also offers a great feature of saving your draft or the message that you are currently composing, every few minutes. So you will not lose any information and Gmail also saves the attachments if any.
To get the message back, click on the Drafts folder link on the left side
Below screenshot explains how it looks like before and after saving.
Before saving the draft
With in few minutes or sometimes less than a minute, Gmail auto saves the draft. You will see a notification as shown below
You can also save the draft manually by clicking on the Save Now button
If you have any questions or suggestions, please post a comment.