spf-discuss
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Re: A couple of thoughts

2004-02-15 11:51:21
wayne <wayne(_at_)midwestcs(_dot_)com> [2004-02-15/12:03]:
MAIL FROM:<>/RCPT TO:<test> is not guaranteed to always work.

Not in practice, because there are broken and/or misconfigured MTAs out
there, deliberately or not (compare with the rfc-ignorant.org database).
But in theory, it is guaranteed to always work. Which is why I do not
like the idea of breaking this too. SPF+SRS break many things already...

Many mailers say "ok" to every RCPT TO: command. Some will delay the
error code for until a data command is issued (I think Yahoo does
this), others will simply accept and create a bounce message.

Yahoo do for some/most addresses, yes. But it still makes sense to use
callback verification with them, as the RCPT TO: will fail for addresses
they blacklist because of known abuse:

  553 VS10-RT Possible forgery or deactivated due to abuse (#5.1.1)

Cheers,
Dan


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    Daniel Roethlisberger <daniel(_at_)roe(_dot_)ch>
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