While this unctionality is not absolutely necessary a lot of apple devices communicates through port 587 i.e TLS, so here is how to set this up.

Make sure that you have a certificate installed on your machine, a self signed cert will do just fine. I have a guide here on how to install a self signed cert Creating a self signed cert. Once this is in place we can proceed.

cd /var/qmail/supervise/qmail-smtpd-tls
vi run

Change the following line xx.xx.xx.xx to the real IP of the machine.

ln -s /var/qmail/supervise/qmail-smtpd-tls /service/

svstat /service/qmail-smtpd-tls/ /service/qmail-smtpd-tls/log/

You should get an output similar to the one below.

/service/qmail-smtpd-tls/: up (pid 9025) 19 seconds
/service/qmail-smtpd-tls/log/: up (pid 9026) 19 seconds

vi /usr/bin/qmailctl

Find the following lines and remove the # in front of all of them.

# if svok /service/qmail-smtpd-tls ; then
# svc -u /service/qmail-smtpd-tls /service/qmail-smtpd-tls/log
# echo "Starting qmail-smtpd-tls"
# else
# echo "qmail-smtpd-tls supervise not running"
# fi

# echo " qmail-smtpd-tls"
# svc -d /service/qmail-smtpd-tls /service/qmail-smtpd-tls/log

# svstat /service/qmail-smtpd-tls
# svstat /service/qmail-smtpd-tls/log

# svstat /service/qmail-smtpd-tls
# svstat /service/qmail-smtpd-tls/log

# echo "Continuing qmail-smtpd-tls"
# svc -c /service/qmail-smtpd-tls

# echo "* Restarting qmail-smtpd-tls."
# svc -t /service/qmail-smtpd-tls /service/qmail-smtpd-tls/log

All of the above lines should look like this.

if svok /service/qmail-smtpd-tls ; then
svc -u /service/qmail-smtpd-tls /service/qmail-smtpd-tls/log
echo "Starting qmail-smtpd-tls"
else
echo "qmail-smtpd-tls supervise not running"
fi

echo " qmail-smtpd-tls"
svc -d /service/qmail-smtpd-tls /service/qmail-smtpd-tls/log

svstat /service/qmail-smtpd-tls
svstat /service/qmail-smtpd-tls/log

svstat /service/qmail-smtpd-tls
svstat /service/qmail-smtpd-tls/log

echo "Continuing qmail-smtpd-tls"
svc -c /service/qmail-smtpd-tls

echo "* Restarting qmail-smtpd-tls."
svc -t /service/qmail-smtpd-tls /service/qmail-smtpd-tls/log