Re: [Exim] Re: Malformed SMTP response

On Wed, 5 Dec 2001 hoh@??? wrote:

> On 5 Dec, Suresh Ramasubramanian wrote:
>
> > Looks like we have the rare case of an MTA which advertises pipelining
> > and doesn't implement it properly, or maybe it took exception to the
> > contents of your bounce message for some reason?
>
> Obviously Exims error reporting was fooled by the pipelining. When
> trying the delivery manually using telnet (without pipelining) I
> get this:
>
> $ telnet mx13.nameplanet.com 25
> Trying 62.70.3.43...
> Connected to mx13.nameplanet.com.
> Escape character is '^]'.
> 220 mx13.nameplanet.com ESMTP
> EHLO mail.mitt-eget.com
> 250-mx13.nameplanet.com
> 250-AUTH=LOGIN
> 250-PIPELINING
> 250 8BITMIME
> MAIL FROM:<>
> 250 ok
> RCPT TO:<user@???>
>
> 553 listed as badmail
> Connection closed by foreign host.
> $
>
> RFC 821 says that 553 is "Requested action not taken: mailbox name not allowed"

Perhaps its an account that some spammer was using to collect replies to
so they've blocked further mail to it? RFC's aside, you can't take any
meaning in smtp responses past the first digit.

2xx xxxxxxxxx = used in the beginning banner, and after any command to
report success

3xx xxxxxxxxx = used when the server is ready to accept multiple line
input (pretty much only a response to DATA

4xx xxxxxxxxx = used to indicate some sort of termporary error - sender
should try again later

5xx xxxxxxxxx = used to indicated a permanent error - do not try that
command/set of commands again..

Anything in the x's is highly site and MTA specific.

> but what do nameplanet.com mean when they say "listed as badmail"? Do they
> object to me sending to that user, or do they dislike the user?
>
> Back to Exim. Exim did not notice the 553 wich should have stopped it from
> trying furter deliveries. Instead it saw the 250 and continues the fruitless
> delivery attempts. Isn't this a serious bug in Exim?
>
>

--