Preventing mail loops, patch?

[Andrew Beverley <andy @ andybev . com>]

I've recently encountered a problem where a misconfigured email server
of a list member was directing list emails back to the list, causing a
mail loop.

The emails were keeping the original headers, so my thought to prevent
this is to add a custom header to the list, and check for the custom
header - for example in taboo-headers.

My question is, does anyone know of any patches to majordomo to do this
automatically, without having to edit each config file, and also without
each looped message being bounced for approval.

Note: because with every pass through the majordomo server another set
of headers was added, the recursive email was eventually stopped
somewhere along the line because of the excessive number of Received
headers.

Thanks,

Andy Beverley