If you know about gmail plus and dot addressing, and use it for verifying uniqueness, then I'll understand. I'll also probably just use mailinator to make the s

If you know about gmail plus and dot addressing, and use it for verifying uniqueness, then I'll understand. I'll also probably just use mailinator to make the second and third accounts anyway, but whatever. If you actually strip the dots and plusses from my email, and start sending stuff to my main address, then I will mark your messages as spam. You need to store the normalized and non-normalized versions of the address. Actually, you need to do this for normalizing on usernames anyway, to make sure you don't mutilate people's Arabic names or anything (Unicode-normalized cursive looks really bad; you need to preserve the original version, while keeping the normalized version around specifically for uniqueness checking).