FYI: Sendmail tries next relay host (including FallbackMXhost) when
remote host rejects message in *greeting* message (including 5?? codes).
[c.m.sendmail reported when sendmail-8.13.3 unintentionally changed it]
IMHO exim may adopt such scheme:
* reject connections from dynamic IPs in greeting message
* use "fallback relay" when rejected in greeting message
In short: "rejecting in greeting message" (5?? or 4??) can be used as a
smart way to hint "try your ISP relay".
What is your opinion about adopting it?
--
Andrzej [en:Andrew] Adam Filip anfi@??? anfi@???
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