People who, when they're giving you their email address say "all lower-case". FOR BASTARD SAKE! It's not 1998, you're meant to understand now that it doesn't matter.

Why stop there? Why not forward me an email that says Microsoft will pay me £10 for every person I forward the email to because they're updating their database, and then get excited because you've had an email saying you've won the El Gordo lottery.