@data = split(/\n/, <<'__EOI__');
root: myself@domain.of-my.own
anotherone: myself@domain.of-my.own
root: yetanother1@domain.of-my.own
__EOI__

$email = 'myself@domain.of-my.own';
foreach (@data) {
   /^root: (?!\Q$email\E)(\S+)/ && print("$1\n");
}

__END__
output
======
yetanother1@domain.of-my.own