Script that allows cPanel-forwarded emails to pass spam authentication

One of our customers wrote a script to resolve an issue where resends cause spam filters to mis-identify the email as spam. I'm submitting their script for consideration of being added into a future version of cPanel, per their request:

1. #!/usr/bin/perl -w
3. # Author: Steve Wolf (stevewolf6@gmail.com)
5. # The standard cPanel mail forwarders don't rewrite any of the mail
6. # headers, which causes SPF tests to fail, of the form:
7. #
8. # Received-SPF: softfail (google.com: domain of transitioning
9. # user@gmail.com does not designate 208.92.162.130 as
10. # permitted sender) client-ip=208.92.162.130;
11. # Authentication-Results: mx.google.com;
12. # dkim=pass header.i=@gmail.com;
13. # spf=softfail (google.com: domain of transitioning
14. # user@gmail.com does not designate 208.92.162.130 as
15. # permitted sender) smtp.mailfrom=user@gmail.com;
16. # dmarc=pass (p=NONE dis=NONE) header.from=gmail.com
17. #
18. # For the most part, these messages get delivered. But we found that
19. # Apple domains (e.g. me.com, mac.com) consider the authentication to be
20. # a hard failure from certain addresses (such as paypal.com).
21. #
22. # This script inserts Resent-* headers into the message before sending
23. # it on, thus allowing authentication to succeed downstream.
24. #
25. # Call this script with the email addresses to which the message will be
26. # forwarded, e.g.
27. #
28. # "| resend.pl user@example.com user@me.com"
30. use POSIX qw(strftime);
31. use Email::MessageID;
33. my @lines;
34. while (<STDIN>) {
35. next if (/^From /);
36. push(@lines, $_);
37. }
39. my $resent_date = strftime("Resent-Date: %a, %d %b %Y %T %z\n",
40. localtime());
41. my $resent_id = "Resent-Message-ID: "
42. . Email::MessageID->new->in_brackets . "\n";
44. foreach my $to (@ARGV) {
45. open(MAIL, "| /usr/sbin/sendmail -oi $to")
46. || die "sendmail failed\n";
47. print MAIL $resent_date, $resent_id, "Resent-To: $to\n", @lines;
48. close MAIL;
49. }