Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!usc!julius.cs.uiuc.edu!ux1.cso.uiuc.edu!mp.cs.niu.edu!rickert From: rickert@mp.cs.niu.edu (Neil Rickert) Newsgroups: comp.mail.misc Subject: Re: Which headers may Sendmail re-write? Message-ID: <1990Dec5.150355.23457@mp.cs.niu.edu> Date: 5 Dec 90 15:03:55 GMT References: <208@frcs.UUCP> Organization: Northern Illinois University Lines: 37 In article <208@frcs.UUCP> paul@frcs.UUCP (Paul Nash) writes: > >We have a dispute between the administrators of a few local machines. >One of the machines runs `sendmail' (for bizzare reasons), and has >a `sendmail.cf' file that re-writes the `To:' and `From:' fields in >all forwarded mail. > >The effect on the headers is roughly as follows (`gatebox' is the >[ficticious] `sendmail' pervert): > > incoming outgoing > > To: user@toaster To: toaster!user@gatebox > From: me@tinytoy From: tinytoy!me@gatebox > In an ideal world, the To: and 'From:' headers would not be rewritten. But in this ideal world only valid addresses would be used, so that rewriting is not required. If your world creates addresses such as 'user@toaster' or 'me@tinytoy', then your world is far from ideal, and the rewriting by sendmail is only rescuing you from a worse fate. A well designed 'sendmail.cf' will try to make sure that all addresses are valid. If they are not valid, it will try to add routing to make sure there is a valid internet address on the outgoing mail. If the incoming address is already valid it is normally rewritten to its incoming form. If you send me mail with a 'From:' address of 'me@tinytoy', and I find that my attempt to reply results in bounced mail and considerable annoyance, you and your postmaster are both going to get a strong message from me complaining about your broken mailers. -- =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*= Neil W. Rickert, Computer Science Northern Illinois Univ. DeKalb, IL 60115. +1-815-753-6940 Brought to you by Super Global Mega Corp .com