Re: email/SMTP validation

Scott Klement wrote:

To validate an e-mail address by checking it's syntax with a regular expression:

http://www.systeminetwork.com/article.cfm?id=52826

Both links require a membership for System iNetwork (but a free "associate" membership should work.)

I took a quick peek at this article (and the site that goes into detail about the recommend regular expression: http://www.regular-expressions.info/email.html). I have a pet peeve about email validity checks. I like to use a '+' in my email address when signing up for online accounts to try to make sure that they don't sell my email address (example below).

The regular expression given in the article would exclude that (syntactically valid) email address. Perhaps 25% of registration forms don't accept addresses in that form, and FWIW I find it rather annoying. If this is a verification check for a customer-facing application, it might be worth choosing a less restrictive regex from the website referenced in the article, and sending a confirmation email as suggested by some earlier posters.


Example:
If my email address is adam@xxxxxxxxxxxxxxx and I'm signing up for an account at www.socialnetwork.com, I'd tell them my email address is adam+nospam.socialnetwork.com@xxxxxxxxxxxxxxxx

I can do this because my email server ignores everything after the '+'. That way if I receive mail from evil@xxxxxxxxxxx to adam+nospam.socialnetwork.com@xxxxxxxxxxxxxxx, then I know that www.socialnetwork.com sold my address or had a security breach.