Rebuild your exim.
cd /usr/local/directadmin/custombuild
./build update
./build set exim yes
./build set eximconf yes
./build set eximconf_release 4.5
./build set spamassassin yes
./build update
./build exim
./build exim_conf
Start, stop and restart the Exim mail server
Start Services:
/etc/init.d/exim start
or
service exim start
Stop Services:
/etc/init.d/exim stop
or
service exim stop
Restart Services
/etc/init.d/exim restart
or
service exim restart
Status of Exim service:
/etc/init.d/exim status
or
service exim status
or
systemctl status exim.service