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SMTP / RFC

Printed From: LogSat Software
Category: Spam Filter ISP
Forum Name: Spam Filter ISP Support
Forum Description: General support for Spam Filter ISP
URL: https://www.logsat.com/spamfilter/forums/forum_posts.asp?TID=2203
Printed Date: 14 March 2025 at 4:02am


Topic: SMTP / RFC
Posted By: Guests
Subject: SMTP / RFC
Date Posted: 14 October 2003 at 8:27am

I know that different vendors look different on the RFC for SMTP - but:

One of my customers is rejected by SpamfilterISP with this error:

>>NOOP         
<<250 Ok
>>MAIL FROM:<x mailto:x@y.com" CLASS="ASPForums" TITLE="WARNING: URL created by poster. - @y.com >
<<501 Polite people say HELO

When receiving direct on my SMTP server, there's no problem....

Any suggestions ?

/ llan


Replies:
Posted By: Desperado
Date Posted: 14 October 2003 at 12:03pm

Allan,

What SMTP server agent gave that silly response?

Dan S.

 

Posted By: LogSat
Date Posted: 15 October 2003 at 12:18am

Actually the "Polite people say HELO" comes from SpamFilter ISP...

:-)

What really matters is the numeric 501 code which is what machines will look at, the description is for the humans...

Roberto F.
LogSat Software

 

Posted By: LogSat
Date Posted: 15 October 2003 at 12:29am

Alan,

The problem is that the remote server is not issuing the HELO (or the EHLO) command after connecting to identify itself.

The RFC does say that clients "should" use the HELO command, rather than "must" use. However since they are not identifying themselves SpamFilter rejects further commands until they issue the HELO. Furthemore, the remote server is not following the RFC "recommended" guidelines, so that is one more reason to assume it's spam.

This option is currently not configurable. We may add an option to disable it in future versions, depending on the volume of requests.

Roberto F.
LogSat Software

Posted By: Desperado
Date Posted: 15 October 2003 at 12:18pm

The "Polite People Say Helo" is from the Spam Filter? .... I have never seen that one.  Under what conditions?

 

Dan S.

 

Posted By: LogSat
Date Posted: 15 October 2003 at 2:36pm

Per RFC, remote clients "should" send either the EHLO or the EHLO commands right after the SMTP server sends the welcome banner. In the HELO command they are to identify themselves with the machine name, ex:

HELO mailgate.logsat.com

After that is done, they can go on with the MAIL FROM and RCPT TO commands.

While the RFC says that this is how things "should" be done, and not "must" be done, SpamFilter requires the HELO command since all legitimate mail servers should follow the RFC. It is a product to fight spam, so it does what it can to ensure mail comes froma legitimate source. If a remote machines tries to issue a MAIL FROM command before sending the HELO, that is when the error occurs.

Roberto F.
LogSat Software

Posted By: Guests
Date Posted: 15 October 2003 at 4:33pm

if one cannot telnet to his logsat server and issue the commands by hand,

 

you better start learning that first before posting ...

ehlo

mail from:

rcpt to:

data

.

rfc822 might help too,

1912 also.

 

no offense,

-eric-


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