To see what your regex actually does you can use YAPE::Regex::Explain: 

use YAPE::Regex::Explain;
my $r=YAPE::Regex::Explain->new(qr/^[\w @.]/);   
print $r->explain();

[download]
This outputs: 
The regular expression:

(?-imsx:^[\w @.])

matches as follows:
  
NODE                     EXPLANATION
----------------------------------------------------------------------
(?-imsx:                 group, but do not capture (case-sensitive)
                         (with ^ and $ matching normally) (with . not
                         matching \n) (matching whitespace and #
                         normally):
----------------------------------------------------------------------
  ^                        the beginning of the string
----------------------------------------------------------------------
  [\w @.]                  any character of: word characters (a-z, A-
                           Z, 0-9, _), ' ', '@', '.'
----------------------------------------------------------------------
)                        end of grouping
----------------------------------------------------------------------

[download]
This might explain why your regex is nog doing what you hoped it would do.

For a better solution look on CPAN, for instance Email::Valid sounds promising

In reply to Re: Simple e-mail validation by eXile
in thread Simple e-mail validation by Anonymous Monk

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