Folks, I've been informed that there is some discussion going on in these two lists regarding our refusal to accept source-routed mail. Well, it's true. We do refuse to accept email with source-routed envelope addresses. I also know what RFC 1123, section 5.2.19 says. I'm also on the IETF DRUMS WG, and I know what the upcoming drafts say with regards to refusing mail (see section 7.5 of <ftp://ds.internic.net/Internet-Drafts/draft-ietf-drums-smtpupd-04.txt >). I quote: It is a well-established principle that an SMTP server may refuse to accept mail for any operational or technical reason that makes sense to the site providing the server. Specifically, source-routed mail has historically been the source of no end of problems, and frequently abused by less savoury types in attempts to ensure that they don't have to deal with their bounces, etc..., we consider this an operational issue and will refuse to accept mail with source-routed envelope addresses. Our general approach is one whereby if we can't determine that we could bounce a message if we had to (i.e., a message comes in for a nonexistant AOL user, or for one whose mailbox is full), then we won't accept that message. The standards are much more forceful on the issue of accepting full responsibility for a mail message once you've accepted the message itself, and that responsibility extends to delivering error messages back to the sender if there is some sort of problem. At some point in time, the RFC 1123 "Robustness Principle" (section 1.1.2) continues the propagation of more and more bad systems, because properly behaved systems are required to continue to be tolerant of poor behaviour, thus ensuring that we'll *never* free ourselves from those shackles. Essentially as much has been observed by various Internet mail experts, many of whom are working on drafting the upcoming standards. I know that I will personally work to ensure that source-routed email is deprecated as much as possible, preferably to the status of "MUST NOT generate/MUST NOT accept". In the meanwhile, AOL will refuse to accept email with source-routed envelope addresses, and I'll contribute my sendmail.cf rewrite rules to Eric Allman in hopes that I can convince him to incorporate them in an upcoming release of sendmail (at least as a FEATURE() you can turn on, if not turned on by default). As Jeff Kell <[log in to unmask]> noted on LSTOWN-L, since you can change the configuration of ListServ so that it doesn't generate source-routed email messages, this shouldn't pose too big of a problem for you. I'd like to see this default changed in upcoming releases of ListServ, so that in the future, email with source-routed envelope addresses will not be generated unless you explicitly configure it to do so. -- Brad Knowles MIME/PGP: [log in to unmask] Senior Unix Administrator <http://www.his.com/~brad/> <http://swissnet.ai.mit.edu:11371/pks/lookup?op=get&search=0xE38CCEF1> -- Brad Knowles MIME/PGP: [log in to unmask] Senior Unix Administrator <http://www.his.com/~brad/> <http://swissnet.ai.mit.edu:11371/pks/lookup?op=get&search=0xE38CCEF1>