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The Graveyard - Products No Longer Supported => D-Link NetDefend Firewalls => Topic started by: Lavdd on October 08, 2011, 01:45:19 AM

Title: HELP: Mail messages can’t pass SMTP ALG
Post by: Lavdd on October 08, 2011, 01:45:19 AM

Mail messages from some mail servers (as it was told before which use additional unsupported smtp instructions) can’t pass SMTP ALG even if in white list and if set process on errors.

Any solutions yet? More and more servers use this unsupported instructions! Is D-Link going to fix it???

I can’t disable ALG as everyone suggest as I will get tons of spam immediately as I use DNSBL Anti-Spam Filter.

Model:   DFL-260
System Time:   2011-10-08 11:49:29
Uptime:   7 days, 19:11:58
Configuration:   Version 75
Firmware Version:   2.27.03.25-14787
 Nov 9 2010
Last Restart:   2011-10-08 02:00:33: New anti-virus database downloaded
AV Signatures:   4000 Signatures
Last updated 2011-10-07 06:00:07

(http://img14.imageshack.us/img14/8969/smtpalg.jpg) (http://imageshack.us/photo/my-images/14/smtpalg.jpg/)

Title: Re: HELP: Mail messages can’t pass SMTP ALG
Post by: Lavdd on October 08, 2011, 03:04:37 AM

It looks related, but it seems not to work:

Version: 2.26.00
Problems Resolved:
16. The SMTP-ALG incorrectly blocked emails sent using the CHUNKING (BDAT)
extension. The ALG has been modified to remove the CHUNKING capability from the server's EHLO response. This allows the emails to pass through the ALG.

From user manual:
The NetDefendOS SMTP ALG does not support all ESMTP extensions including Pipelining and
Chunking. The ALG therefore removes any unsupported extensions from the supported extension
list that is returned to the client by an SMTP server behind the D-Link Firewall. When an extension
is removed, a log message is generated with the text:
unsupported_extension
capability_removed
The parameter "capa=" in the log message indicates which extension the ALG removed from the
server response. For example, this parameter may appear in the log message as:
capa=PIPELINING
To indicate that the pipelining extension was removed from the SMTP server reply to an EHLO
client command.
Although ESMTP extensions may be removed by the ALG and related log messages generated, this
does not mean that any emails are dropped. Email transfers will take place as usual but without
making use of unsupported extensions removed by the ALG.

Title: Re: HELP: Mail messages can’t pass SMTP ALG
Post by: Lavdd on November 26, 2011, 04:40:11 AM

any solutions so far?