Re: [MTA] Problems using sendmail and exim...
On 24 Jun 1999, Martin Bialasinski wrote:
> Thant's fine. Although the remote end misbehaves. Here is an excerpt
> from the exim manual:
>
> The RFCs mandate that a server must not reject a message because it
> doesn't like the HELO or EHLO command, or indeed if there isn't a
> HELO or EHLO command at all.
That is right but RFC's are not law. They are Requests for Comments. Many
are never put into practice, many are PARTIALLY put into practice, and
many are simply documentations of practice that sprang out of common use
without an RFC.
RFC's should be taken with grains of salt. In THEORY you are correct but
in PRACTICE most hosts require HELO oe EHLO to match the reverse lookup of
the IP address making the connection. Live with it. The internet changes
all the time and the RFC's often take a few years to catch up and document
current best practice.
Any RFC written more that 3 years ago was written when the internet was a
much different place than it is now.
EXAMPLE:
Most RFC's even describe all kinds of things that are never put into
practice. When was the last time you used SVR records in DNS introduced in
RFC 2052? There is not a single client that I know of that uses them yet
they would make load balancing and the pointing of services to
non-standard ports VERY simple. It would get rid of a lot of port
redirectors by placing the host/port information in the DNS level.
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