On 17-Jul-2001 John Kielkopf wrote:
> The RFC suggest the following:
>
> 550 Requested action not taken: mailbox unavailable [E.g., mailbox not
> found, no access]
> 551 User not local; please try <forward-path>
> 552 Requested mail action aborted: exceeded storage allocation
> 553 Requested action not taken: mailbox name not allowed [E.g., mailbox
> syntax incorrect]
>
> Also see:
> A receiver-SMTP SHOULD send only the reply codes listed in section 4.2.2 of
> RFC-821 or in this document. A receiver-SMTP SHOULD use the text shown in
> examples in RFC-821 whenever appropriate.
>
> A sender-SMTP MUST determine its actions only by the reply code, not by the
> text (except for 251 and 551 replies); any text, including no text at all,
> must be acceptable. The space (blank) following the reply code is considered
> part of the text. Whenever possible, a sender-SMTP SHOULD test only the
> first digit of the reply code, as specified in Appendix E of RFC-821.
RFC821 list even this for the mailbox full error :
452 Requested action not taken: insufficient system storage
and I think that a 4xx class error is more correct than a 5xx one.
- Davide
