On Mon 26 Feb 2018 at 10:45:29 (+0000), Curt wrote: > On 2018-02-23, Brian <a...@cityscape.co.uk> wrote: > > On Thu 22 Feb 2018 at 11:58:18 -0600, David Wright wrote: > > > >> On Mon 19 Feb 2018 at 18:39:02 (+0000), Brian wrote: > >> > On Mon 19 Feb 2018 at 10:23:56 -0600, David Wright wrote: > >> > > >> > > $ cat /etc/mailname > >> > > alum > >> > > >> > Debian's exim4 README says that mailname should be a FQDN. I find that > >> > useful for sending mail to "anotheruser". > >> > >> Sorry, but I haven't been able to work out what you mean. > >> Is "anotheruser" a username on the same system, somebody or > >> some machine on the LAN, or something different? > > > > Exim will qualify all unqualified addresses with mailname. "anotheruser" > > could be a user on the system or have an email account elsewhere. > > With mailname as gmail.com a mail sent to or cc'ed to tom123 would go to > > tom...@gmail.com. > > > > I'm informed over at the wiki that Exim doesn't read /etc/mailname; > rather, at configuration time, when requesting the system's "visible > name," Exim stores the value of visible name in /etc/mailname (amongst > other places). But it doesn't subsequently read that file for that > value, and changing /etc/mailname has no effect on Exim. > > You probably already knew this, but there was a certain ambiguity. > > https://wiki.debian.org/EtcMailName
There *is* a certain ambiguity. Exim(3) is clearly saying that /e/m is written whenever you reconfigure exim (in an appropriate manner) and never read. Exim4 implies the opposite but I'm not sure I believe the wiki here. Looking at the configuration files, whatever is written to /e/m is also cached in /var/lib/exim4/config.autogenerated as ETC_MAILNAME, so exim4 has no need to revisit the file. Anyway, this is a sideshow: I'm an honest member of this debate and wouldn't mislead by posting the contents of /e/m if I had changed it after running dpkg-reconfigure exim4-config. Taking stock, and making things more concrete, were I to make my canonical hostname into foo.home what exactly does "home" buy me? The answer so far seems to be that HELO foo.home will open doors to "mail servers" that might previously have been firmly shut. However, it's not clear to me that the people saying this aren't relaying mail on port 25 (leaving aside 465).. I'm more interested in the "home LAN", where people are submitting new messages (usually on port 587) to systems that naturally, nowadays, require authentication more rigorous than a matching domainname and dotty address. Cheers, David.
