On Thu, 2 Mar 2000, Daniel Buchholz wrote:
> The session transcript is:
>
> >>> RCPT To:<[user@domain]>
> <<< 550-Open realy - see ...[ORBS]
> <<< 550 mail from [IP] rejected: administrative prohibition
>
> Fairly common I think.
> But just the next line says
>
> 550 <[user@domain]>... User unknown
That is because the sending MTA thinks it knows what 550 means and adds
this incorrect information. Even good old RFC 821 allows for different
uses:
550 Requested action not taken: mailbox unavailable
[E.g., mailbox not found, no access]
The revision of 821 (currently in preparation) says
550 Requested action not taken: mailbox unavailable
(e.g., mailbox not found, no access, or command rejected
for policy reasons)
--
Philip Hazel University of Cambridge Computing Service,
ph10@??? Cambridge, England. Phone: +44 1223 334714.