On Tue 15 Nov 2016 at 15:02:54 +0000, Joe wrote: > On 15/11/2016 14:10, Brian wrote:
> >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. I'm convinced it can all of these things but my needs are mostly accomodated by the setups described in the Debian documentation. > >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. Are you sure that is the default? brian@desktop:~$ telnet localhost 25 Trying ::1... Connected to localhost. Escape character is '^]'. 220 desktop ESMTP Exim 4.84_2 Tue, 15 Nov 2016 15:38:31 +0000 helo claptrap 250 desktop Hello localhost [::1] mail from:brian 501 brian: sender address must contain a domain mail from:brian@localhost 250 OK rcpt to:brian@desktop 250 Accepted -- Brian.
