[Pkg-exim4-users] sporadic invalid helo -- setting primary_hostname

[J G Miller]

At 16:06h, on Saturday, February 27, 2016,
in message <56D20FCA.2020402 at redowl.ca>,
on the subject of "[Pkg-exim4-users] sporadic invalid helo",
Jonathan Addleman explained -

 > When the lookup succeeds, the HELO uses the proper domain. But it seems 
 > my host has a slightly wonky DNS server, and it occasionally fails. In 
 > that case, it uses $primary_hostname. From the docs I've read, 
 > (https://wiki.debian.org/PkgExim4UserFAQ#How_does_exim_find_out_its_host_name_to_use_in_HELO.2FEHLO.3F) 
 > this value is not set, and should be getting the full domain, but it 
 > seems to be only getting the hostname.

Perhaps this will help ...

In 

       /etc/exim4/main/01_exim4-config_listmacrosdefs

I have

       MAIN_HARDCODE_PRIMARY_HOSTNAME  = host.fqdn

and in

       /etc/exim4/main/02_exim4-config_options

I have

       primary_hostname             = MAIN_HARDCODE_PRIMARY_HOSTNAME

and also (but this is probably not relevant to your problem)

       qualify_domain               = MAIN_HARDCODE_PRIMARY_HOSTNAME

So you need to ensure that primary_hostname is set to something,
preferably via a "global" macro (global in the sense that it can be
reused for one or more "specific" macro instances) in 01_exim4-config_listmacrosdefs.