Author: Russell King Date: To: Bill Hacker CC: exim Subject: Re: [exim] Problem with HELO
On Wed, Mar 09, 2005 at 08:20:46PM +0800, Bill Hacker wrote: > Looks like (probable) ratware tried to connect with 'raw' IP instead of
> <domain>.<tld>
>
> See 'domain_literals', generally NOT allowed by default/ most sysadmins'
> choices, despite RFC clause.
But "IP literal" is not a "raw" IP address.
raw ip address: 192.168.254.2
ip literal: [192.168.254.2]
See RFC2821 4.1.3, or RFC821 3.5 and 4.1.2.
So, "EHLO 192.168.254.2" is syntactically incorrect, whereas
"EHLO [192.168.254.2]" isn't.
