On 7/30/12, valdis.kletnieks@vt.edu <valdis.kletnieks@vt.edu> wrote:
On Mon, 30 Jul 2012 10:07:37 -1000, William Herrin said: The Internet uses DNS. You use some other scheme at your own peril,
Aside from that RFC974 [Page 3] gives mailers significant leeway in deciding how to handle errors: " Mailers are expected to do something reasonable in the face of an error. The behaviour for each type of error is not specified here, but implementors should note that different types of errors should probably be treated differently. " Attempting to find another path for an apparently unroutable message (all MX offline) is not entirely out of the question. You may not assume that such measures will not be attempted, if anyone could consider it a 'reasonable' error handling procedure. I will echo that; go back to the robustness principal of being liberal in what you accept.... You should either not listen on port 25, or you should not create that A record pointing to a mail server that won't actually accept mail. When "yourdomain.example.com" has an A record, all the services listening on that address are services for the domain. "Relay not allowed" to the same domain may be considered nonsensical, and a mailer converting its error recovery attempt into a permanent error at that point, may be reasoned. -- -JH