Re: ASSP and NOOP - ReadList.com

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ASSP and NOOP
\ Daniel L. Miller (30 May 2007)
. \ Ralf Hildebrandt (30 May 2007)
. . \ Daniel L. Miller (30 May 2007)
. . . \ Ralf Hildebrandt (30 May 2007)
. . . . \ Victor Duchovni (30 May 2007)
. . . . . \ Ralf Hildebrandt (30 May 2007)
. . . . \ Daniel L. Miller (30 May 2007)
. . . \ (Wietse Venema) (30 May 2007)
. . . . \ (Wietse Venema) (30 May 2007)
. . . . . \ Daniel L. Miller (30 May 2007)
. . . . . . \ (Wietse Venema) (30 May 2007)
. . . . . . . \ Daniel L. Miller (30 May 2007)
. . . . . . . . \ (Wietse Venema) (30 May 2007)
. . . . . . . . . \ Daniel L. Miller (30 May 2007)
. . . . . . . . . . \ Victor Duchovni (30 May 2007)
. . . . . . . . . . \ (Wietse Venema) (30 May 2007)
. . . . . . . . . . . \ Victor Duchovni (30 May 2007)
. . . . . . . . . . . \ Daniel L. Miller (31 May 2007)
. . . . . . . . . . . . \ Daniel L. Miller (31 May 2007)
. . . . . . . . . . . . . \ Victor Duchovni (31 May 2007)
. . . . . . . . . . . . . . \ Daniel L. Miller (31 May 2007)
. . . . . . . . . . . . . . . \ Victor Duchovni (31 May 2007)
. . . . . . . . . . . . . \ (Wietse Venema) (31 May 2007)
. . . . . . . . . . . . . . \ Daniel L. Miller (31 May 2007)
. . . . . . . . . . . . . . . \ Victor Duchovni (31 May 2007)
. . . . . . . . . . . . . . . \ (Wietse Venema) (31 May 2007)
. . . . \ Daniel L. Miller (30 May 2007)
. . . . . \ Victor Duchovni (30 May 2007)
. . . . . . \ Daniel L. Miller (30 May 2007)
. . . . . . . \ Victor Duchovni (30 May 2007)
. . . . . . . . \ Daniel L. Miller (30 May 2007)

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Subject:	Re: ASSP and NOOP
Group:	Postfix-users
From:	(Wietse Venema)
Date:	31 May 2007

Daniel L. Miller:
> Wietse Venema wrote:
> > ASSP is a proxy. It forwards responses from Postfix to the
> > remote SMTP client.
> >
> > The response "503 .. nested MAIL command" means that ASSP messed up
> > its conversation with Postfix.
> >
> > Like this:
> >
> > Client X connects
> >
> > ASSP forwards MAIL FROM from client X to Postfix
> >
> > ASSP replies 4xx to RCPT TO from client X
> >
> > Client Y connects
> >
> > ASSP forwards MAIL FROM from client Y to Postfix
> >
> > Postfix replies with 503 .. nested MAIL command
> >
> > In other words, ASSP does not reset the connection after the MAIL
> > FROM from client X, so that Postfix is still in MAIL FROM state
> > when ASSP forwards the MAIL FROM from client Y.

> Could this be the result of a cached connection?

ASSP sent multiple MAIL FROM commands to the local MTA.

These MAIL FROM commands were from DIFFERENT REMOTE CLIENTS.

My MTA's MAIL FROM command was rejected with "503 .. nested MAIL
command" because ASSP screwed up the protocol with the local MTA.

Wietse