Re: [Exim] exim HELO ack

> > Note that:
> > - at least some Windows machines seem not to send a fqdn in their
> > HELO string (despite being told both their host and domain names.)
> OE6 on win2k appears to send the netbios name in the HELO. On reading
> RFC821 this doesn't appear to break any standard, but then again doesn't
> exactly adhere to the suggestions made later in RFC2821 either (namely
> that in the absence of a FQDN the client SHOULD send an address literal
> which on my reading equates to a dotted quad - IP address???):

It's microsoft, they don't usually follow rfcs. it's not a microsoft
standard.

> Personally I'm not overwhelmed by spammers or other abusers who misuse the
> HELO/EHLO command and I can't justify denying or dropping clients based
> solely on the fact that they don't use a FQDN or even an address literal
> in their HELO/EHLO - a lot of my users use OE which appears to not adhere
> to this anyway.

Actually, you can. How many spammers authenticate to your server?
You could put the helo check in the mail/rcpt and if they aren't
authenticated, drop them. Of course if you have local users, you exclude
them from the check entirely.

--
Lab tests show that use of micro$oft causes cancer in lab animals