Modules such as Data::Validate::Email are the preferred way to do that trick.

However if I take your code and make it into a runable sample:

use strict;
use warnings;

my $value = 'me.you@mydom.com';

if ($value =~ /(@.*@)|(\.\.)|(@\.)|(\.@)|(^\.) / ||
    $value !~ /^.+\@(\[?)[a-zA-Z0-9\-\.]+\.([a-zA-Z]{2,3}|[0-9]{1,3})(
+\]?)$/
    ) {
    print "Bad email\n";
} else {
    print "Good email\n";
}
[download]

it prints:

Good email
[download]

which is not quite what you describe.