[Rspamd] Add hint to composite, minor

data/conf/rspamd/local.d/composites.conf

@@ -16,6 +16,7 @@ SOGO_CONTACT_EXCLUDE_FWD_HOST {
 SOGO_CONTACT_SPOOFED {
   expression = "(R_SPF_PERMFAIL | R_SPF_SOFTFAIL | R_SPF_FAIL) & ~SOGO_CONTACT";
 }
+# SPF checks against envelope, so we do not exclude SPF valid mail
 SPOOFED_UNAUTH {
   expression = "!MAILCOW_AUTH & !MAILCOW_WHITE & !RSPAMD_HOST & !SIEVE_HOST & MAILCOW_DOMAIN_HEADER_FROM";
   score = 5.0;