[exim] relay_domains not being honored?

I'm getting a "relay not permitted" error on RCPT of a mail message I
send from my workstation to a foreign destination via my exim 4.68
server.

The mail is catching on the section in exim.conf:

--
   require message = relay not permitted
           domains = +local_domains : +relay_domains
--

I've put the domain of the workstation I'm testing from into the
"domainlist relay_domains =" directive but I'm still getting the
"relay not permitted" message dropped in my log. Also added it to
local_domains but still couldn't get past the above domain check.