On Wed, 2013-03-20 at 15:04 +0000, Jethro R Binks wrote: > I may be having a dim day today but ... isn't that
> "X-Authentication-Warning ... set sender to" a sendmailism, not exim?
Yes. It's not in the Exim source code - so that's a very good spot.
Looking back through this thread I see that various config changes and
restarts of an Exim daemon have taken place, but nothing has changed.
That will be because PHP is calling "/usr/lib/sendmail" (or equivalent),
which is either a binary or a symlink to an installed Sendmail binary.