Re: [Exim] allowing local_part with suffix in sender

> Use -bh, possibly with -d9 as well, to run a fake SMTP session (see
> manual for details). That should show why it isn't verifying. If you are
> still stuck, post the configuration of your director and the output of
> -bh for us to comment on.

Thanks, I hadn't had cause to use that option before. Very handy.

After digging around some more I think the cause of the problem was
something that had been lurking in the initial configuration I set up
a couple of years ago when we first migrated to exim.

I had based the new director on the existing "localuser" director
(but using a new transport which uses the appendfile driver),
including the option "driver = localuser", and if I now understand
the manual correctly that was causing exim to call getpwnam() to
check the local part ("username-boxname") and I suspect that is why
it was complaining about "unknown local part".

I changed the driver option to "driver = smartuser" and, once I
had worked out that I then also needed to include the option
"user = $local_part", that seemed to fix the problem.

I then tried reverting to using "driver = localuser" whilst retaining
the option "user = $local_part", and that seems to work too.

Although it is now working, I would still appreciate it if someone could
take a moment to explain to me what adding "user = $local_part" is
actually doing in this context that is making the difference
between the director working and it reporting "unknown local part".

Thanks,

Dave