Mac Mail's annoying little habit

There are things about Mail that I like, but there are some things that frustrate me! For example, why doesn't Mail have a button so that you can step through your messages? And why does Mail check the spelling of the whole message each time you send a reply?

For the last point I found a solution quite by accident. If, like me, you have "check spelling" set to happen when you send a message, a second click of the send button stops any further checking and sends the message as it is.

So, once you've checked the bits you want to check, just click send and you will avoid all the unnecessary checking of the rest of the message.