#!/usr/bin/perl -p

# m-filter -- filter headers

# Edit this script to your own preferences.

BEGIN {
	sub header { $_ =~ shift .. not $next =~ /^[ \t]/ }
	sub skip { $_ = '' }
}

($_, $next) = ($next, $_);
skip if header qr/^X-(?!(
	  Mailer
	| Rspamd-\S+
):)/xi;
skip if header qr/^(
	  Received
	| Received-SPF
	| (DKIM|DomainKey)-Signature
	| ARC-\S+
	| IronPort-\S+
):/x;

END { print $next }