Aye, it's surprising who can do the RFC and who just does a simple regex

I wrote the libvldmail to RFC-validate e-mail addresses. Contributors welcome!

In HPUX a long time ago, a standard character was treated, IIRC, as a backspace. Can't remember if it was a colon or caret or percent sign. But a fellow sysadmin had one in his NIS password and couldn't log into our HPUX machines!

Yeah, years ago I read a "trick" to managing email with Gmail. If you add a + and any text just before the @ in a Gmail address, the mail will still come to the main address. I'd sign up for things using the format User+Company@gmail.com and use that address to automatically sort emails into folder or delete/block them if they ended up spamming me. Unfortunately, at least one company that let me sign up for their site that way later migrated to a different system, and my old login with the plus sign stopped working. They were able to fix it for me, so that my account's email address no longer used the portion between the + and @, but it's made me reluctant to try that again. I do still sometimes do it when I'm signing up for freebies and think they'll spam me, though, especially in cases where I don't really care if I can log in to the site again in the future.

Ditch them all and do it yourself.