From ncr-sd!ncrcae!hubcap!gatech!amdcad!rpw3 Thu Mar 31 15:45:36 PST 1988 >In article <23560@hi.unm.edu> kurt@hi.unm.edu (Kurt Zeilenga) writes: >-What is considered defacto standard way(s) of rewriting "a!b%c"? The "%" is neither a "!" nor a "@", and thus is (or *should* be) left alone by any of the transport/routing programs. It *may* be interpreted by "local" mail delivery systems, and in particular is handled by "sendmail", and many SMTP mailers (although seldom by non-sendmail UUCP mailers). The defacto standard way, and the reason for the "%" at all (as opposed to "@"), is to defer any rewriting unless you are system "a", in which case you have already stripped the "a!", and are trying to deliver mail to a local "user" named "b%c". At this point (and *only* at this point), you notice the "%", and re-write "b%c" as "b@c", and then do whatever you do locally with "@" addresses (including sending it back out again). If you are not "a", you send it via UUCP to "a" (if you know how :-). The purpose of the "%" is to avoid the ambiguity that arises with mixed "!" and "@". By the way, "%" is often used in the SMTP world. The address "b%c@a" means exactly the same as above: If you are system "a", the "b%c" is a "local-part", which you can (but are not required to) re-write to "b@c". So, for example, in SMTP-land you can often send a "mail-echo" be sending to "me%my-system@other-system". p.s. Note that the usual example, "a!b@c", *cannot* be parsed corectly unless you know what kind of transport it came in on. If it came in on SMTP, then "a!b" is the "local-part", and you should send it to "a" via UUCP. If it came in on UUCP, then "b@c" is the "user", and you should send it to "c" with SMTP (or maybe UUCP, depending on your mail system). Such a mixed-mode horror should *never* be generated locally! If you *have* to send to a "domain" via a UUCP first hop, then use full-bang domain addressing: a!c.dom.ain!b Mailers such as "smail" understand this form. Rob Warnock Systems Architecture Consultant UUCP: {amdcad,fortune,sun,attmail}!redwood!rpw3 ATTmail: !rpw3 DDD: (415)572-2607 USPS: 627 26th Ave, San Mateo, CA 94403 From ncr-sd!hp-sdd!hplabs!ucbvax!ucdavis!ccdan Thu Mar 31 15:45:58 PST 1988 In article <23560@hi.unm.edu> kurt@hi.unm.edu (Kurt Zeilenga) writes: > What do you do with something like: > a!b%c (where a, b, and c could domainized) > > I prefer: > a!b@c (deliver to c) > because many folks here address things to a!b and I will forward them > to d for forwarding to c. So I give d a "a!b%c@d". Now, I could give > d "a!b@c@d", but that has two '@', or just "a!b@c". > > What is considered defacto standard way(s) of rewriting "a!b%c"? the '%' hack isn't actually documented anywhere that i know of. for this reason, it could be considered the "least binding token". it's been my experience that it is far better to resolve host!left%right on the '!' and thus send to "host" for delivery. the advantage of the % hack is that it allows for mail to pick it's way through systems that will hopefully leave the '%' parts alone until the the very last. if you start giving it higher precedence than '!', the results will be unpredictable. the only time you would resolve on the '%' in an address of left%right is if the '%' is the only recognized routing token left. --dan dorough, systems programmer, ccdan@ucdavis.edu, (916)752-3420 From ncr-sd!ncrcae!hubcap!gatech!bloom-beacon!tut.cis.ohio-state.edu!mailrus!nrl-cmf!ames!killer!mjbtn!root Mon Apr 18 15:05:11 PDT 1988 In article <379@tness7.UUCP>, mechjgh@tness7.UUCP (Greg Hackney ) writes: > Using the Elm mailer, I type the address: > > murthy@svax.cs.cornell.edu > > Elm reads the paths file, and changes it to the > shortest route: > > bellcore!rutgers!murthy@svax.CS.CORNELL.EDU > > rutgers kicks it back as an UNKNOWN host, but it > WILL accept this address: > > bellcore!rutgers!svax.cs.cornell.edu!murthy > > Is it rutgers, Elm, or my domains and paths file that is screwed, > or all of the above? You would probably be safest to have your rewrite rules in your domains file write the address to the whole bang path address that rutgers did accept. It has to do with the precedence given to '@' over '!' on some systems, while the '!' is given precedence over '@' on others. This of course makes two entirely different addresses out the address you entered. For example, say '@' over '!', h1!h2!h3!user@system.domin would be interpretted as (h1!h2!h3!h4!user)@system.domain which means that from system, send via uucp to h1!h2!h3!h4!user. If it were '!' over '@', then the same address would breakup as h1!h2!h3!h4!(user@system.domain), which is what I assume you are wanting. My mailer, smail, gives precedence of '@' over '!'. I had similar experiences with trying to send mail via ucbvax to a user on BITNET via ucbvax. I gave it 'h1!h2!h3!ucbvax!user@system.BITNET'. What happened was that it managed to get to ucbvax without some other system in between from parsing it differently (ie, it made it to ucbvax on the bang path safely), but at ucbvax, it was parsed to be mailed to 'h1!h2!h3! ucbvax!user' and of course, h1 was not connected directly to ucbvax, so it returned it as host unknown. This is sort of a crude explanation, but once I changed my rewrite rules in the domains file to all bang path generation, it worked like a charm. My mailer actually rewrites everything to bang paths too, so I can't be too far off. Hope this helps. Mark. -- Mark J. Bailey _____________________________________________________ _________________\ _____| > @ Nashville Knoxville _/ / + ____'' > Jackson + <*> MURFREESBORO _/ / "From the Heart of Middle Tennessee!" ___> > + Memphis Chattanooga _< <______________________________________________+_______/ JobSoft UUCP: ...!{ihnp4,cbosgd,mit-eddie}!killer!mjbtn!root Design & Development Co FIDO: Mark Bailey at Net/Node 1:116/12 Murfreesboro, TN USA