To configure saslauthd to provide authentication for Exim4.
SASL can be used when Exim is supporting local user email accounts.
The first step is to install the sasl2-bin package from the Main repository.
sudo apt-get install sasl2-bin
Edit the /etc/default/saslauthd configuration file and set START=no to:
START=yes
Next the Debian-exim user needs to be part of the sasl group in order for Exim4 to use the saslauthd service:
sudo adduser Debian-exim sasl
Now start the saslauthd service:
sudo /etc/init.d/saslauthd start
Exim4 is now configured with SMTP AUTH using TLS and SASL authentication.