I have two interacting systems in one we are using Castle Validator for our validation, the other is coded by hand, I need to ensure the email validation between these two systems is a match; the problem is I have not been able to find documentation of the Regex that castle uses for email.
There is this question but the links provided are all dead.
After looking through the repo history I was able to find the regex (separated into multiple lines for readability):
^([a-zA-z0-9_\-\.\'\+]+)
@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\.)+))
([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$
A side note: this regex is still pretty broken with how the @[ipaddress] is allowed.
For example this: [email protected]] is registered as valid as would this: johndoe@[111.111.111.com