Standardized email regex

Question

Why is there not a standardized email regex? I was recently involved in a project where we had a hickup where the email passed our email regex but failed when creating the MailMessage object. A small error but it had rather big consequences

• Is the MailMessage constructor using a email regex when checking if an email address is correct?
• Why are there so many different versions of an email regex?

this is an ASP.Net application and we used the System.Net.MailMessage object

This is a duplicate of Regexp recognition of email address hard?

Answer 1

Because even this regex doesn't match every valid email address:

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There are some things that are just better left to other languages.

Answer 2

See this answer for more (too much!) information