> > So for me, the exim email system on the desktop computers is > > exclusively used by the Linux operating system. I do not enable > > incoming email, so all mails are generated by the various services > > that come with Linux. Some of these services are operated > > intentionally by me, like logcheck and monit. But some are just > > basic system services that tend to report relevant information via > > email, often to root. > > As I suspected, you're sensibly trying to be able to tell at a glance > which machine a message is from. This use-case is the main purpose of > the address rewritng proposed in the Postfix null-client guide in the > MULTI_INSTANCE doc.
Another, much more brute force way (if you don't have a common /etc/passwd file that's somehow distributed around) is to change the /etc/passwd GECOS field for relevant accounts to have the machine's name in it. This assumes you have a limited number of such accounts and that your machine names are fixed (you don't rename them around), but it's very light-weight and easy. We do this (for root) with: chfn -f "$(hostname) root" root It wouldn't be hard to do this for a list of system logins, especially if you didn't care greatly about duplicating their current GECOS values. This has been quite handy to tell at a glance what important system is sending us root email for some reason, without having to look at the Received: headers or hope that whatever generated the email put the hostname in the Subject:. (This is less cool than address rewriting and other tricks, though.) - cks -- ## subscription configuration (requires account): ## https://lists.exim.org/mailman3/postorius/lists/exim-users.lists.exim.org/ ## unsubscribe (doesn't require an account): ## exim-users-unsubscr...@lists.exim.org ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/