> On Nov 30, 2015, at 8:11 AM, Al Iverson <[email protected]> wrote: > > On Mon, Nov 30, 2015 at 9:19 AM, Ned Freed <[email protected]> wrote: > >>> Do you seriously think that Google has special-case header parsing to deal >>> with >>> spam from Cornell students' infected computers? No, they just use machine >>> learning. >> >> I have no idea what Google does, but I can assure you Received: field >> analysis >> does play a role in spam filtering elsewhere. And even if it didn't, there's >> more to mail operations than spam filtering. > > I work for an email service provider dealing with rather large volumes > of mail, yet Received header analysis still plays an important role > for us in troubleshooting operational issues. It would be a tremendous > loss to lose received headers or the IP address information in those > headers. You raise Google as an example; Gmail occasionally seems to > delay message delivery. The internal received hops in a Gmail header > tell you that it's Gmail, not the sender, delaying that delivery of > the message, because the message is likely queued on some internal > server for some period of time, after sender's initial handoff. > > Some of us do actually process this data at some level of scale to > identify issues. > > Not only do I seriously believe it, but I have also personally > observed AOL to use special-case header parsing to deal with certain > types of mail, to more directly answer your question.
I've heard AOL people discuss "second received header parsing", and effective filtering of infected dorm computers behind University smarthosts was one of the use cases. This isn't something speculative, it's something that's been in use for years. Cheers, Steve _______________________________________________ Shutup mailing list [email protected] https://www.ietf.org/mailman/listinfo/shutup
