It's just bad code, not a conscious decision to block any specific e-mails. Here's the code of a local construction project's e-mail subscription form: valid

It's just bad code, not a conscious decision to block any specific e-mails. Here's the code of a local construction project's e-mail subscription form: validationexpression = "^([a-zA-Z0-9_\\-\\.]+)@[a-z0-9-]+(\\.[a-z0-9-]+)*(\\.[a-z]{2,3})$"; It assumes all e-mails end in 2 or 3 letters after a dot. I run into it all over the place. I can't redeem reward points on my Visa card because the redemption 'shopping cart' requires an e-mail to notify you when the rewards ship, and says mine isn't valid. I was blocked signing up for a checking account online because of my "invalid" e-mail, but opened the same account at a branch with the same e-mail address, where they now e-mail my statements.