Re: odd behavior in enforcing of message size limits

[Tom Samplonius <tom@uniserve.com>]

On Fri, 21 Jun 1996, Ken Pizzini wrote:

> I have smtpserver running with a "-M8388608" option set;
> its enforcement of this limit seems odd:
> 
> 23107w	220 mm1_1 Server ESMTP 2.99.27 #2 ready at Fri, 21 Jun 1996 11:59:47 -0700
> 23107#	remote from [165.121.12.17]
> 23107r	EHLO ember.spry.com
> 23107w	250-mm1_1 Hello ember.spry.com
> 23107w	250-SIZE 8388608
> 23107w	250-8BITMIME
> 23107w	250-PIPELINING
> 23107w	250-EXPN
> 23107w	250-VRFY
> 23107w	250-XDSN
> 23107w	250-X-RCPTLIMIT 10000
> 23107w	250 HELP
> 23107r	MAIL From:<ken@spry.com> BODY=8BITMIME SIZE=36708613
> 23107w	552 The message size exceeds fixed maximum message size
> 23107#	-- pipeline input exists 33 bytes
> 23107r	RCPT To:<zen@delrina.net>
> 23107w	250 Ok; can accomodate 36708613 byte message
> 23107#	-- pipeline input exists 6 bytes
> 23107r	DATA
> 23107w	354 Start mail input; end with <CRLF>.<CRLF>
> 23107#	(mail_priority=0)
> 23107w	552 Message size exceeded fixed maximum size for acceptable email
> 23107#	aborted: session terminated
> 
> 
> First off, it seems to me that the smtp transport agent on "ember"
> (running Zmailer 2.99.26) should have stopped after the 552 error
> following the "MAIL From:" line.  Given that it went on anyway,
> the "RCPT To:" response should also have returned an error, rather
> than saying it would accept.  Finally, the DATA command should
> reject as if there were no "MAIL From:" line, since that command
> returned an error.

  Since command pipelining is being used, the remote host sent all the 
commands at once (notice "pipeline input exists").

  Allowing the DATA command makes sense.  The remote host wouldn't see a 
DATA command failing, and the message would be input as SMTP commands.   
Better to let DATA command succeed, and drain rest of the buffer, and 
then throw it away.

Tom