Whoops, that last RE fails against just "@example.com".
I think I've got it working with negative look-behind, but try to think of other test cases.
while( <DATA> ) {
my( $expect, $string ) = split;
my $result = $string =~
m/ @ (?: .* (?<! [@.] bar) \. )? example\.com $ /xi
? 'match' : 'fail';
printf " Got result '%s' when expecting '%s' on '%s'\n",
$result, $expect, $string
unless $result eq $expect;
}
__END__
match smith@example.com
match jones@example.com
match jones@foo.example.com
fail jones@bar.example.com
fail jones@foo.bar.example.com
match jones@baz.example.com
match jones@bbar.example.com
fail jones@bar.example.com.com
fail rednose@reindeer.org
fail smythe@exzample.com
fail teacher@make-an-example.com