The Underscore Archives

on 23/4/07 17:02, Michael Trim at Michael.trim at ibltd.com wrote:

> I have no idea what this means but I imagine plenty here do

The very first thing that happens when 2 mail servers start talking is, the
sending server says "HELO " followed by either its fully qualified domain
name or its IP address in square brackets. E.g.

HELO mail.watershed.co.uk

or

HELO [195.10.250.253]

Anything else is in breach of the RFCs, and the receiving mail server is
entitled to tell the sending server to sod off.

> Diagnostic-Code: SMTP; 550 Please use your real hostname when saying
> HELO (not HSP-AV01)

What's happened here is your mail server has said

HELO HSP-AV01

"HSP-AV01" is not a fully qualified domain name (i.e. it should be
HSP-AC01.a-domain-or-some-sort.com), and so the Uni mail server disconnected
your mail server.

My mail servers will also reject bad HELO messages - it does *wonders* for
cutting down on spam.

Oliver.