On 15/11/2016 14:10, Brian wrote:
On Tue 15 Nov 2016 at 08:00:31 -0500, Greg Wooledge wrote:
On Mon, Nov 14, 2016 at 04:29:35PM -0600, David Wright wrote:
As your own hostname -f produces not dots, what approach do you
use to shut exim up, or do you just ignore (or suppress) the message?
I have (control over) a bunch of computers, and they're not all configured
the same. The machine I believe you refer to is this one:
wooledg@wooledg:~$ hostname
wooledg
wooledg@wooledg:~$ hostname -f
wooledg
This is a dual-boot Windows/Debian workstation on my desk at work.
Here's the /etc/hosts:
wooledg@wooledg:~$ cat /etc/hosts
127.0.0.1 localhost
127.0.1.1 wooledg
Exim wants to see a fqdn in the 127.0.1.1 line, written as specified in
hosts(5):
IP_address canonical_hostname [aliases...]
The canonical_hostname is used for the HELO/EHLO.
Default, can be overridden by the primary_hostname configuration, which
can be overridden again by helo_data in individual transports.
My mail server's hostname does not exist in public DNS, like many small
mail servers it is behind NAT, not directly exposed to the Net. My
public MX hostname is not the same as the server's hostname.
Also exim4 can handle mail for multiple domains, using a separate HELO
for each if required, and the per-transport setting allows even finer
HELO control if you have a use for that.
With most large ISPs
it is not taken much notice of but there are servers which (rightly or
wrongly) would do a reverse lookup on wooledg and, getting a negative
response, reject the mail. Basically, you will get away with the line
you have when you use an understanding smarthost. I think Postfix
could behave in the same way.
That's fairly common, the exim4 default if enabled is to check that the
HELO is resolvable at all, not that it matches anything specific. It's a
few years since I last did it, but when I used telnet to talk to remote
mail servers I used a well-known six character domain name as HELO to
save typing, one to which I had no entitlement, and nothing ever complained.
--
Joe
