Peter J. Holzer wrote:
250 2.0.0 Verbose mode
250 2.1.0 <hurtta(_at_)localhost>... Sender ok
050 <root>... aliased to hurtta
250 2.1.5 <root>... Recipient ok
But note an important difference: There is no "-" after "050", so the
RCPT command returns two results (050 and 250) in this case, not a
single result with conflicting return codes. LMTP and draft-hall-prdr
extend the data command in a similar way.
I agree. No one is saying multiple continuation codes should be
supported because it goes against the 25 year old written formal
specificaiton of BREAKING on the first non-continuation line.
In this case, the client issued the VERBosity command so it is full
control of the situation. So this scenario is not the same issue here,
but it does show that these NON-STANDARD reply codes are used in practice.
But as an important and related side note, please read the intepretation
that been published in a TCP/IP Reference BOOK with a interesting
"The TCP/IP reference even you can understand"
which technically supports the usage of non-continuation PRELIMINARY codes: