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Sticking out neck: why specify conversions ?
I've been following this discussion a while with some confusion; why does
the issue of converting from one format to another format have to infect the
specification of a point to point message protocol ?
Let me suggest the following:
An MTA receiving an 8 bit command (EMAL et al) should accept it
ONLY if it can guarantee 8 bit delivery to the final recipient.
With this approach we get the benefit that a sending UA can get notice
directly from the local MTA that 8 bit transport is not possible, and then
apply whatever conversions the user want. The cost of this is that anyone
accepting MX for BOTH new and old SMTP sites have to be able to tell which
sites can handle 8 bit mail and which can't.
Whether this is achieved with a neighboring hosts list, a new DNS RR,
actually connecting to the recipient host and doing an EVFY, or asking the
man in the moon, should be of no concern to this protocol specification.
Any entity that accepts mail for 8 bit delivery but then converts it to a
7 bit format, or to some nonstandard 8 bit format, is not an MTA but a
gateway; if such gateways are wanted, their operation should be specified
separately from the transport protocol, not in RFC-YYYY.
Am I the only one who has seen the light ?
Paul Svensson _ /| - Every absurdity needs a champion to defend it -
SM5SJS \'o.0' Scandinavian System Support Fax: +46 13 115193
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