On Dec 16, 2013, at 11:26 AM, Murray Kucherawy <[email protected]> wrote: > There's a general but unenforced rule that the thing in an MX record can't > be a CNAME; the MX has to be canonical.
I wouldn't say 'unenforced', I'd say that "rule" (from RFC 2181) is loosely enforced. 10.3. MX and NS records The domain name used as the value of a NS resource record, or part of the value of a MX resource record must not be an alias. Not only is the specification clear on this point, but using an alias in either of these positions neither works as well as might be hoped, nor well fulfills the ambition that may have led to this approach. This domain name must have as its value one or more address records. Currently those will be A records, however in the future other record types giving addressing information may be acceptable. It can also have other RRs, but never a CNAME RR. Matt > I have no idea how or why this applies to ADSP, however, since it only > cares about TXT records or the presence of A/MX, not the things to which > they refer. > > On 12/13/13 9:53 AM, "Benny Pedersen" <[email protected]> wrote: > >> John Levine skrev den 2013-12-13 04:00: >>>>> If example.net is a parked domain you can then protect it this way: >>>>> _dmarc.example.net CNAME _dmarc.parked.example.com >>>> >>>> CNAME preserve DNSSEC ? >>> >>> Yes, of course it does. CNAME is a fundamental part of the DNS and >>> always has been. >> >> i have seen CNAME used in MX records, its fundemental it works as >> designed >> >> same problem some domains used in ADSP setup with is now depricated, >> just still used in spamassassin in wild >> >>>> it does not work in ADSP >>> >>> I don't know what you mean by "does not work" here, but it doesn't >>> matter because ADSP is dead, and DMARC does not use it. >> >> MX and ADSP must NOT be ised with CNAME >> >> >> _______________________________________________ >> dmarc-discuss mailing list >> [email protected] >> http://www.dmarc.org/mailman/listinfo/dmarc-discuss >> >> NOTE: Participating in this list means you agree to the DMARC Note Well >> terms (http://www.dmarc.org/note_well.html) > > > _______________________________________________ > dmarc-discuss mailing list > [email protected] > http://www.dmarc.org/mailman/listinfo/dmarc-discuss > > NOTE: Participating in this list means you agree to the DMARC Note Well terms > (http://www.dmarc.org/note_well.html) _______________________________________________ dmarc-discuss mailing list [email protected] http://www.dmarc.org/mailman/listinfo/dmarc-discuss NOTE: Participating in this list means you agree to the DMARC Note Well terms (http://www.dmarc.org/note_well.html)
