Re: email/SMTP validation

Hi Adam,

If you look over my article again, you'll see that I tried to address situations like that by stating the following:

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There are some caveats with most regular expressions used for validating e-mail, including the one that I'm about to demonstrate. Please read the following Web site for details about this regular expression, including the caveats:
http://www.regular-expressions.info/email.html

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My hope was that the reader would actually follow my advice in the article and read the web page and learn about the pros and cons. The goal of the article was to show that this CAN be done in RPG (something that many people probably didn't realize). IT should be trivial to change the sample program to use a different RE if you don't like the one I picked.



Adam Glauser wrote:

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.