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Stop Validating Email Addresses With Your Complex Regex

davidcel.is

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Re: Stop Validating Email Addresses With Your Complex Regex

#101

Post by jerf »

jfb wrote: post #94
jerf wrote: post #76

Earlier quoted context omitted.

Because it's not obvious. Ask developers to recite the rules for correct email address, and most of them will get it laughably wrong. I blame the standard, which is far more "featureful" than is actually required, but that is the way it is.

It's featureful because it's old . Who routes email to UUCP any more? Just look at the sections of 5322 that are devoted to "Obsolete Syntax".

Actually, I was just thinking the core error was something else; conflating routing with identity. bob@subgenius.com is a routing instruction, 'J. R. "Bob" Dobbs' is a human identity, and '"J. R. 'Bob' Dobbs" ' is just a mess.

Re: Stop Validating Email Addresses With Your Complex Regex

#102

Post by kiallmacinnes »

nostromo wrote: post #90

I don't think this is good advice. From a previous startup we saw a ton of signups like, "john@gmail" and the like. Obviously this person will not get a validation email -- and in all likelihood will not be able to log in to his account when he returns. It's best to catch him when he's entering the information.

I've seen a huge number of users do exactly this.

Anyone who says "let the confirmation email handle it" clearly only has HN readers as customers. The type silly stuff, then email support to complain they never received the confirmation.

Re: Stop Validating Email Addresses With Your Complex Regex

#104

Post by hippich »

I believe that he is right that you should not rely on regexps to validate emails, but I disagree that you should stop it completely.

First of all - less incorrect emails sent - less chances to get marked as spam host. Second - it is very easy to catch obvious errors user can do on front end and ask user to correct it. These two is big ones imho

Re: Stop Validating Email Addresses With Your Complex Regex

#105

Post by [deleted] »

riffraff wrote: post #97
nostromo wrote: post #90

I don't think this is good advice. From a previous startup we saw a ton of signups like, "john@gmail" and the like. Obviously this person will not get a validation email -- and in all likelihood will not be able to log in to his account when he returns. It's best to catch him when he's entering the information.

still there is a difference between validating * @ * . * and trying to check if parenthesis are matched correctly.

[deleted]

Re: Stop Validating Email Addresses With Your Complex Regex

#106

Post by blowski »

I worked in a lead-generation agency for some time. We were doing competitions that could produce 50-100K entries per day, where the end result was a marketing email encouraging you to buy something.

So we did lots of multivariate testing, with permutations of regex patterns, MX record validation, sending a confirmation email, client-side only, server-side only, etc.

What we found was that a decent regex pattern (we used \b[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b, taken from http://www.regular-expressions.info/email.html), with MX record validation and common junk domains blocked (e.g. mailinator.com) produced the largest conversion rates in the follow-up email.

In other words, less validation produced more entries, but they would have been lower quality, which affected our sender reputation and cost more. The confirmation email was awful for conversion. YMMV.

Re: Stop Validating Email Addresses With Your Complex Regex

#107

Post by whirligig »

bane wrote: post #79
smackfu wrote: post #34

The question is why people are validating the email in the first place. * to ensure it is deliverable? Well, then you better send them an email. * to let people know when they misread the labels and put something that was clearly not an email in the email field? A simple check for an at-sign is usually sufficient. * because some tester opens a ticket saying you can enter an invalid email in the email field? Yeah, tha…

Because most users couldn't type their own email address, or even a properly formatted email address to save their life. "My email address is joe.aol or was it aol.com@joe? Wait joeaol@com?"

I'd say nothing of value is lost in that case. These people are very costly to support. Email has been in common use for at least 20 years. They need to step up to the plate and learn at this point.

Re: Stop Validating Email Addresses With Your Complex Regex

#108

Post by chrismarlow9 »

nostromo wrote: post #90

I don't think this is good advice. From a previous startup we saw a ton of signups like, "john@gmail" and the like. Obviously this person will not get a validation email -- and in all likelihood will not be able to log in to his account when he returns. It's best to catch him when he's entering the information.

Worked on custom mailing scripts for a few larger newsletters which had no regex based validation. It was "add and forget" on every form submission. Of the failed emails, forgetting the ".com/.net/.org" on the email was the most common mistake I saw as well.

Re: Stop Validating Email Addresses With Your Complex Regex

#110

Post by [deleted] »

riffraff wrote: post #97
nostromo wrote: post #90

I don't think this is good advice. From a previous startup we saw a ton of signups like, "john@gmail" and the like. Obviously this person will not get a validation email -- and in all likelihood will not be able to log in to his account when he returns. It's best to catch him when he's entering the information.

still there is a difference between validating * @ * . * and trying to check if parenthesis are matched correctly.

[deleted]
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