Taking time before you reply.
Take time before you reply.
You could be working your dream job, and I guarantee there'd still be that one colleague that would really get on your tits. Every email they send you will make you just want to throw your laptop out the window, go and hunt them down from the 3rd floor, and shake them until they've admitted they're ~trying~ to be hard-work just for the sake of it.
I've sent many emails back to this kind of colleague after they've properly got on my wick, read back over it later, and realised it was probably a little too blunt.