Use Mail::RFC822::Address. Also, the Regular Expression Library has some pretty interesting constructs.

As to your regex, I don't see anything wrong in it, and it works with a couple of test cases as it should: 

$ perl -e 'print "valid\n" if ("foo\@bar" =~ m/^[a-zA-Z_\-.0-9]+@[a-zA
+-Z_\-.0-9]+$/);'
valid
$ perl -e 'print "valid\n" if ("j.random.hacker\@perlmonks.com" =~ m/^
+[a-zA-Z_\-.0-9]+@[a-zA-Z_\-.0-9]+$/);'

[download]

Of course, tests can never show the absence of errors. But I'm willing to bet you have a problem somewhere else in the program.

UPDATE: Seems like others beat me to it... I just remembered that there was some nice discussion about this over at The Daily WTF.

--
print "Just Another Perl Adept\n";

In reply to Re: regexp to only allow for formally valid email addresses by vrk
in thread regexp to only allow for formally valid email addresses by fraktalisman

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