+PH/16 Recognize SMTP codes at the start of "message" in ACLs and after :fail:
+ and :defer: in a redirect router. Add forbid_smtp_code to suppress the
+ latter.
+
+PH/17 Added an extra condition to the default value of delay_warning_condition
+ so that it is now:
+
+ ${if or {
+ { match{$h_precedence:}{(?i)bulk|list|junk} }
+ { match{$h_auto-submitted:}{(?i)auto-generated|auto-replied} }
+ }{no}{yes}}
+
+ The Auto-Submitted: header is standardised, whereas I don't think
+ Precedence: ever was.
+