[exim] TLS configuration on FreeBSD 10.1 amd64

Hi,

I am trying to set up an exim mail server on freebsd-10.1-amd64. I am
fairly new to mail server installation, although 9 years back I managed
to set up qmail on freebsd 5.x

I have to set up ingoing and outbound email for users of my company Rat.
Our domain is rat.com, which is hosted by an external provider who
provides DNS and mail services. I have to migrate the mail server to my
own machine. Essential facilities are webmail support and spam control
support.

I installed exim from the ports, using GnuTLS instead of vanilla TLS. It
seems to be working okay: at least port 25 is being listened on, as
netstat/sockstat reports. I then tried configuring exim to enable
STARTTLS for all hosts. One of the main TLS options is tls_certificate

I set the following :
tls_certificate = /etc/ssl/certs/dovecot.pem
tls_privatekey = /etc/ssl/private/dovecot.pem

The dovecot pem's apparently got installed on my system while I was
doing something with dovecot+qmail. The pem files are world readable.

Now when I start exim, I get :

/etc/ssl/private # service exim start
Starting exim.
2015-03-17 14:41:27 Exim configuration error in line 152 of
/usr/local/etc/exim/configure:
main option "tls_certificate" unknown
/usr/local/etc/rc.d/exim: WARNING: failed to start exim

What might be wrong ? I tried using a self-signed cert created using
'openssl ca' facility, but I continue to get the same error. So how I do
enable TLS/STARTTLS ?

Thanks for any help.

--

Regards,

Manish Jain