Drafts for email you compose but not yet sent (either because of not having internet connection or other reason), are kept.
You can View your Folders using: Swipe from left edge or by tapping the top left corner logo, and choosing the desired Account. Choose Drafts see your drafts.
On iOS
Drafts for email you compose but not yet sent (either because of not having an internet connection or other reason), are kept.
You can View your Folders using the burger menu | Choose Drafts to see your drafts.
On Desktop
Drafts for email you compose but not yet sent (either because of not having an internet connection or other reason), are kept.
You can View your Folders using the burger menu | Choose your desired account | Choose Drafts to see your drafts.