[RFCI-Discuss] multi-MAIL commands appearing in the same mail-transaction?

[Alex van den Bogaerdt]

On Tue, Jun 06, 2006 at 08:46:15AM -0400, Derek J. Balling wrote:

> >It say 'The <reverse-path> can contain more than just a mailbox'.As  
> >I think,each mailbox mean a MAIL FROM command,so there would permit  
> >multi-MAIL commands.Is it right?
> 
> No, I would interpret that as something like, it could have  
> +notation, or other arguments, stuff like that. Not that multiple  
> MAIL commands are valid.

Indeed, do not interpret this as "...more than just _one_ mailbox."
More does not refer to an amount, it refers to source routing.

This said: I think multiple mail from is allowed, like this:

helo ...
mail from: ...
rcpt to: ...
data
.
mail from: ...
rcpt to: ...
data
.
quit

or like this:

helo ...
mail from: ...
rcpt to: ...
rset
helo ...
mail from: ...
rcpt to: ...
data
.
quit

(that 'rset' could be left out if ehlo is used).


> >helo 163.com
> >mail from:<abcd at 163.com>
> >mail from:<efgh at 163.com>
> >rcpt to:<xxxx at gmail.com>
> >data
> >quit

> GMail's implementation is following a literal interpretation of  
> RFC2821. The second MAIL command is "a new mail transaction" and thus  
> it "resets all its state tables and buffers", so essentially the  
> first MAIL command is completely gone, its state erased.

A 2nd MAIL FROM command inside a mail transaction is forbidden. See
rfc2821 2.3.8 and 4.1.4


A mail session that will contain mail transactions (so: could be more than
one transaction) has to start with EHLO or HELO.

A mail transaction is:  1(MAIL FROM), 1*(RCPT TO), 1(DATA)
The indicator which ends the DATA segment also ends the mail transaction.


HTH
Alex