Ned Freed wrote in the message archived at
<http://www.IMC.ORG/ietf-smtp/mail-archive/msg05917.html>:
...
But even this isn't really necessary to specify precedence among
protocols. The specification could say that pop/pops/imap/imaps
records should be considered as a group, and absent client
configuration to the contrary should be used in the order specified
by their individual priority fields. For example, an imaps record
with a higher priority than any imap record would indicate imaps
is preferred over imap.
RFC 2782 appears to allow schemes like this. But whether it's worth
defining such a thing is another matter. My personal opinion is that
it's just a bit outside my comfort zone in terms of complexity, but if
others feel strongly that servers should be able to specify protocol
preferences this is a way to do with it with no additional DNS records
or supplementary protocols.
Folks,
please take a look at the draft Olafur Gudmundsson and I recently
have posted to clarify RFC 2782 (and hence intended for PS),
http://tools.ietf.org/html/draft-gudmundsson-dnsext-srv-clarify-00
According to these clarifications (if approved), such specific rules,
*if and only if unambiguously specified* would IMO well be possible.
Absent such application-specific documentation, the standard SRV
naming and usage rules apply. Cyrus Daboo's draft would likely be
the proper place to incorporate such specific rules, if desired.
Kind regards
Alfred.
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