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Re: Minor is. It's not a pardigm change

2008-03-30 19:23:22

John R Levine wrote:
To run an email server, today, an existing host only needs to make the server software operational. No other change is required. For example, no coordination with DNS administration is required.

I suppose that's still true in theory, but when's the last time you saw a non-spam message sent to someone(_at_)[12(_dot_)34(_dot_)56(_dot_)78] or saw an MTA deliberately configured to accept mail to dotted quad addresses? Every useful mail server has at least an A record.

John, maybe I missed something in the discussion, but I thought your proposal was to mandate MX records for IPv6 e-mail hosts? Support for domain literals seems unrelated.

Requiring an MX record for every mail host certainly would be a paradigm shift. The historical use of the MX record is to identify which hosts are responsible for the incoming E-mail for a domain, not identifying the specific hosts that are able to accept E-mail. There are many situations where a sending MTA coerces the RHS of the bounce address to its own hostname to ensure that bounces are returned specifically to the sending host. This might be done for list management, capacity management, internal corporate organization, security, or a number of other reasons. If MX records were required, then they'd have to be added for every one one of these sending hosts. I know of many organizations for which this would be a significant administrative burden.