[Dovecot] submission_host problem

[David Ford]

this and several other features are tools i use with tremendous success
at battling spam.  every MTA connection that violates protocol by making
an assumption or posts invalid data for the SMTP phase, gets kicked off
with a 421.

-david

On 11/16/2011 09:11 AM, Marc Haber wrote:
> I have always interpreted the standard in the way that a client MUST
> NOT assume that the server supports pipelining before it has
> advertised PIPELINING. Since PIPELINING is only advertised after the
> client has identified itself as being ESMTP compliant by saying EHLO
> instead of HELO, I believe that the client MUST wait with his EHLO
> until the server has shown its banner. Forcing synchronization is a
> very effective means of spam protection since most spam bots just
> blast away with EHLO, MAIL FROM without bothering to wait for the
> server's banner. Greetings Marc