David Nicol wrote:
> On 1/6/06, Matt Sergeant <[EMAIL PROTECTED]> wrote:
>> On 6 Jan 2006, at 13:58, Les Mikesell wrote:
>>
>>> Is there an RFC requirement that the connecting host MUST
>>> wait before sending anything?
>> Yes, see RFC 2821 section 4.3.1.
>
> Which says that the earlytalker error should be a 554 not a 450.
Not exactly. 554 is defined in 4.2.2 as:
554 Transaction failed (Or, in the case of a connection-opening
response, "No SMTP service here")
which isn't exactly the same thing and in fact isn't true. We will accept SMTP
transactions here, just not until you play nice.
We are sending a 4xx error because it is a temporary failure that the client can
fix (by waiting for the banner) instead of a 5xx permanent error. 421 is a
possible alternative, but it also carries the wrong implication:
421 <domain> Service not available, closing transmission channel
(This may be a reply to any command if the service knows it
must shut down)
that there is something wrong with the server, instead of the client.
John
