Thank you to all for your responses. I'm learning a lot from them. I was curious about the multiple froms in the received header. It's unconventional to me. In my twenty years dealing with mail I can't recall receiving a message with this kind of header before. Also, in Mailman there no filter for this, although there is for too many recipients. It's as if Mailman assumes single sender is a given.
Is multiple froms allowed in the RFC(s)? I can't think of a case when it would be a good thing, but then I'm just a mail administrator from the Shire. Jose ....................................................... Jose Hales-Garcia UCLA Department of Statistics > I've recently been getting spam that has the first received header filled in > with multiple users. This is an example. > > Received: from 79.14.233.16 (account <user1@domain>, > <user2@domain>, > <user3@domain>, > <user4@domain>, > <user5@domain>, > <user6@domain>, > <user7@domain>, > <user8@domain>, > <user9@domain>, > <user10@domain>, > <user11@domain>, > <user12@domain>, > <user13@domain>, > <user14@domain>, > <user15@domain>, > <user16@domain>, > <user17@domain>, > <user18@domain>, > <user19@domain>, > <user20@domain> HELO domain) > by domain (CommuniGate Pro SMTP 5.2.3) > with ESMTPA id 107437582 for <user1@domain>; Mon, 11 Apr 2011 10:19:10 > +0100
