[Mimedefang] SMTP Pipelining, and GREYLISTING

[Chris Myers]

----- Original Message ----- 
From: "Cormack, Ken" <kcormack at acs.roadway.com>
To: <mimedefang at lists.roaringpenguin.com>
Sent: Thursday, March 25, 2004 12:59 PM
Subject: [Mimedefang] SMTP Pipelining, and GREYLISTING


> Please read the thread below.  If you impliment greylisting with
MIMEDefang,
> you MIGHT want to disable sendmail's support for PIPELINING.  (See rfc
2920:
> SMTP Service Extension for Command Pipelining)
>
> You can check your sendmail to see if it currently supports pipelining, as
> follows:
>
> sendmail -d0.1 -bt < /dev/null
>
> If you see PIPELINING in the "Compiled with" options, then pipelining
> support is active.  To disable support for pipelining (which is enabled by
> default if you compile the sendmail source tar-ball), you need to add the
> following statement to your devtools/Site/site.config.m4 and recompile
> sendmail.
>
> APPENDDEF(`conf_sendmail_ENVDEF', `-DPIPELINING=0')

PIPELINING can also be disabled in the sendmail access database file with
the srv_features item.  Just add the following line to your /etc/mail/access
file and rebuild the access database:

srv_features:                   P

(the whitespace is composed of TAB characters, NOT spaces!).

If you need to, other options include:

    A    suppress SMTP AUTH
    S    suppress offering STARTTLS
    V    turns off request for client certificate during TLS handshake

If you have more than one option, use commas to separate the values.  You
can also control this per-host or per-domain, with

srv_features:host.domain    options
srv_features:domain    options

Chris Myers
Networks By Design