Once it’s in your Drafts folder, you can give a moment’s thought to whether it’s ready to send, before selecting Message – Send from the menu bar.
When you’ve written an email, then, you will be prompted to save it as a draft before closing.
If you are prone to firing off emails you later regret sending, you could remove the ‘send’ button from the menu bar altogether by customising the toolbar from the View menu. Unfortunately, there is as yet no handy delay system for Apple’s Mail app, so the workaround we suggest is purely psychological. If you suddenly remember why that email must not be sent, simply click ‘undo’ in the yellow bar that will appear on the screen. During that time, you have the opportunity to rack your brains for potential problems with the message. This feature works by delaying sending your email for up to thirty seconds. A quick search for ‘Undo Send’ will locate the option.
This is a Google Labs option, so to enable it, navigate to Settings, then Labs. Google understands your terror at the current irretrievability of emails – and has come up with an easy solution in its Undo Send addon for Gmail.