> Sorry for not mentioning the version.
>
> Is there any way to do this in 4.52? I didn't see anything
> in the book, and adding the option failed.
>
The 4.50 spec on the website lists it:
http://www.exim.org/exim-html-4.50/doc/html/spec_24.html#CHAP24
Remember, it is a transport option and needs to be set on your transport, so
something like:
Transport:
rt_smtp:
driver = smtp
hosts = status.geneseo.edu
rcpt_include_affixes = true
Is that what you had ? If not, change it and see if it works.
John