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Re: Fixing Greylist - Its usage of 451 vs 450

2007-11-18 12:21:37

Hi Hector,
At 21:44 17-11-2007, Hector Santos wrote:
However, I believe you are saying the exception to the literal reason rule would be the "catch all" 450 response code when the reject reasons does not fit 451 or 452 because those two codes are deemed sacred for those two "finer" specific server rejection literal reasons only.

My reply is based on draft-klensin-rfc2821bis-05. I'm not suggesting that the 450 reply code is a "catch all". As you said, I tried to see where the reject reason fits in. The aim is to convey the "message" clearly, within the guidelines of the RFC, to the other end instead of them second-guessing what might be wrong.

 - 451 seems to be reserved for the server admission that
   it just experienced a backend server problem but it is
   deemed to be temporary, i.e, its not the sender's fault,
   therefore it should try again,


Section 4.3.2 (Command-Reply Sequences) of RFC 2821 lists each command with its usual possible replies. It does not mention 450 in the DATA phase. There is a change in rfc2821bis to include the 450 reply code there.

Any further comments will be off-list.