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> From validating email addresses Guys, no. Send an email. https://davidcel.is/posts/stop-validating-email-addresses-with-regex/ https://davidcel.is/posts/stop

> From validating email addresses Guys, no. Send an email. https://davidcel.is/posts/stop-validating-email-addresses-with-regex/ https://davidcel.is/posts/stop-validating-email-addresses-wi...

kuschku 9y ago
That works if you have content that you know is an email address. If you have free-form content, and need to identify email addresses in it, then you can’t just email every subset of that text.
- lowmagnet 9y ago
  > That works if you have content that you know is an email address. That's what validation is. You're talking about finding email addresses, which I agree that regex is relatively OK at doing, but there are still lots of edge cases in the spec that are irregular.
mhd 9y ago
Depends on the use case. For forms, a preliminary sanity check doesn't hurt, e.g. when the user enters their username and password, instead of email & password (accepting either would be best, but you can't always do that).
- deleted 9y ago
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- tyingq 9y ago
  Mailcheck is great for this. People constantly make typos when entering emails. This utility suggests john.doe@gmail.com if they type in john.doe@gnail.com. But, it's their choice...it just suggests corrections. My logs show that it helps a lot. Bounced emails from orders dropped by more than half. https://github.com/mailcheck/mailcheck/blob/master/README.md https://github.com/mailcheck/mailcheck/blob/master/README.md
Invisig0th 9y ago
The article you link to addresses just the one use case where you are registering a new user. Email addresses in business applications are just as often NOT the address of your user. Sales contacts, managers, points of contact, customer support addresses, etc. -- none of these should ever be validated by sending an e-mail. So you still need to validate the hard way in plenty of scenarios.
- kqr 9y ago
  ...but unless you actually send an email it is still just as unvalidated as it was before. Regexes aren't a tool to determine that a string refers to a mailbox capable of receiving mail. If you use regexes (or any other method of that does not send emails) all you're saying is that you don't actually care whether or not the string points to a recipient (much less the correct recipient). And don't get me wrong. It is absolutely okay to not care whether or not the string refers to a correct recipient. Most places that make me write my email have no business caring about it. But please also then make the field optional.
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  - Invisig0th 9y ago
    Regex validation cannot verify that an email address is functioning any more than it can verify that a phone number is functioning. But if an address or a number passes formatting checks, one can indeed consider that data "validated". That's what that term means in the business software development industry. We're verifying if the data entered COULD be correct, not double-checking that it IS correct. You are correct to say that those emails may still bounce, and the phone calls may also not go through. We completely understand that. For this reason, in very specific situations (like registering a new user), we do take that extra step to make sure the communication channel actually works. But there are plenty of situations where that makes absolutely no sense, and/or adds very little value for the cost. Knowing the difference between these two very different use cases certainly does not indicate that these people "don't actually care" about the accuracy of their data.
davidkuhta 9y ago
In fairness, the author does make note of that: Note - In a real-world application, validating an email address using a regular expression is not enough for many situations, such as when a user signs up. Once you have confirmed that the input text is an email address, you should always follow through with the standard practice of sending a confirmation/activation email.

> From validating email addresses Guys, no. Send an email. https://davidcel.is/posts/stop-validating-email-addresses-with-regex/ https://davidcel.is/posts/stop-validating-email-addresses-wi...

kuschku 9y ago

That works if you have content that you know is an email address. If you have free-form content, and need to identify email addresses in it, then you can’t just email every subset of that text.

lowmagnet 9y ago
> That works if you have content that you know is an email address. That's what validation is. You're talking about finding email addresses, which I agree that regex is relatively OK at doing, but there are still lots of edge cases in the spec that are irregular.

mhd 9y ago

Depends on the use case. For forms, a preliminary sanity check doesn't hurt, e.g. when the user enters their username and password, instead of email & password (accepting either would be best, but you can't always do that).

deleted 9y ago
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tyingq 9y ago
Mailcheck is great for this. People constantly make typos when entering emails. This utility suggests john.doe@gmail.com if they type in john.doe@gnail.com. But, it's their choice...it just suggests corrections. My logs show that it helps a lot. Bounced emails from orders dropped by more than half. https://github.com/mailcheck/mailcheck/blob/master/README.md https://github.com/mailcheck/mailcheck/blob/master/README.md

Invisig0th 9y ago

The article you link to addresses just the one use case where you are registering a new user. Email addresses in business applications are just as often NOT the address of your user. Sales contacts, managers, points of contact, customer support addresses, etc. -- none of these should ever be validated by sending an e-mail. So you still need to validate the hard way in plenty of scenarios.

kqr 9y ago
...but unless you actually send an email it is still just as unvalidated as it was before. Regexes aren't a tool to determine that a string refers to a mailbox capable of receiving mail. If you use regexes (or any other method of that does not send emails) all you're saying is that you don't actually care whether or not the string points to a recipient (much less the correct recipient). And don't get me wrong. It is absolutely okay to not care whether or not the string refers to a correct recipient. Most places that make me write my email have no business caring about it. But please also then make the field optional.
- deleted 9y ago
  [deleted]
- deleted 9y ago
  [deleted]
- Invisig0th 9y ago
  Regex validation cannot verify that an email address is functioning any more than it can verify that a phone number is functioning. But if an address or a number passes formatting checks, one can indeed consider that data "validated". That's what that term means in the business software development industry. We're verifying if the data entered COULD be correct, not double-checking that it IS correct. You are correct to say that those emails may still bounce, and the phone calls may also not go through. We completely understand that. For this reason, in very specific situations (like registering a new user), we do take that extra step to make sure the communication channel actually works. But there are plenty of situations where that makes absolutely no sense, and/or adds very little value for the cost. Knowing the difference between these two very different use cases certainly does not indicate that these people "don't actually care" about the accuracy of their data.

davidkuhta 9y ago

In fairness, the author does make note of that: Note - In a real-world application, validating an email address using a regular expression is not enough for many situations, such as when a user signs up. Once you have confirmed that the input text is an email address, you should always follow through with the standard practice of sending a confirmation/activation email.