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Re: New guy to this list..

2005-05-11 07:26:35

--On Wednesday, 11 May, 2005 19:22 +0530 Vijayan
<vijayan(_at_)jataayusoft(_dot_)com> wrote:

Hi All,

This is Vijayan from Bangalore,India, working as a Soft.Engr.
Presently i'm doing a project in a Mailing application.. my
module is SMTP.

I have some couple of doubts in SMTP standards..

1. What is the actual difference between HELO and EHLO
commands.. what is the use of these two different commands..
when to use which... and why..???

Use of HELO indicates support for (only) SMTP as defined in RFC
821.  Use of EHLO indicates that one is able to handle the
extended options and responses of RFC 2821 and related
standards.   If you are doing any sort of new development,
support of RFC 2821, and hence EHLO, is strongly recommended
since a number of new features depend on it.

2. I had read in the RFC , that this commands (HELO/EHLO) r
used to tell what is the Client SMTP the SMTP Server. (is it
correct ??).. then in that case even if i'm sending a command
like " EHLO 123 or EHLO junk / EHLO pheeeen" it is accepting..

The EHLO command normally contains the official domain name of
the client.   However, that text is largely informational as
authentication, if needed, should come in other ways.
Consequently, rejection of an EHLO command because the domain
name is not valid is prohibited.  However, invalid syntax is
another matter: it is permitted for a server to reject an EHLO
(or HELO) command to reject all three of the examples you give
since they are clearly not fully-qualified domain names or,
using an explicit exception in RFC 2821, IP addresses.  Some
servers do reject on that basis, others do not.

plese clarify my doubts..

hope to get an earlier response..

Hope that helps.