Technically speaking, there are things out there like
http://www.ex-parrot.com/pdw/Mail-RFC822-Address.html (just to show, that
very very few people do an actually 100% correct email validation)
2014-11-25 15:39 GMT+02:00 Tim Ward t...@telensa.com [firebird-support] <
firebird-support@yahoogroups.com>:
>
>
> On 25/11/2014 13:29, sirhamac...@gmail.com [firebird-support] wrote:
>
>
>
> select
>
> iif('em...@testdomain.com' similar to
> '([_a-zA-Z\d\-\.]+@[_a-zA-Z\d\-]+(\.[_a-zA-Z\d\-]+)+)','ok','fail')
>
> from rdb$database
>
> Says 'invalid string' and 'invalid pattern', but the pattern it´s the same
> in other languages for validate email address.
>
> Well, just a couple of general observations:
>
> - there is no such thing as a regular expression that can validate an
> email address, at best you can get an approximation that works "quite
> often" but still gets it wrong sometimes
>
> - there are dozens of languages all with slightly different rules for
> regular expressions, it's not a surprise if any non-trivial regular
> expression needs changing between languages, you just have to read the
> rules for the new language.
>
> --
> Tim Ward
>
>
>
