Comment 64 for bug 119899

(In reply to comment #60)
> I've always been able to filter messages to a Yahoo or Google group by adding
> "Reply-To" as a custom header and filtering on "Reply-To:
> <email address hidden>".
>
> As for the "Newsgroups" header, that belongs to Usenet news, not mail. News
> filtering is handled separately and doesn't support custom headers yet. You
> may want to vote for bug 16913 which addresses that problem.
>

Ok, so you don't like those examples. I personally use the "Received" header for spam filtering. (e.g. Received header contains "209.104.219."). The spammers "from" is too variable. Subject filtering can't be effective until we get wildcarding implemented (and possibly not even then). But I can identify an IP address range for many spammers. Once identified I can redirect their future messages, but the current inability to apply a filter to the inbox prevents me from being able to clean out the stuff they sent before I identified that IP range.

If you can think of an counter argument to my example, I am sure somebody else can provide yet another use. Regardless of any specific responses to specific examples, there /are/ uses for this capability.

(Personally I don't really see why "Received:" should have to be a custom header anyway...)