We need to reconfigure exim4 to enable outgoing email (exim4 got installed earlier as a prerequisite for the mysql server).
# dpkg-reconfigure exim4-config
- Select "internet site; mail is sent and received directly using SMTP" then configure as appropriate for your site.
- Enter the FQDN of your site when asked
- Listen on all IP addresses (i.e., make list blank)
- Other destinations for which mail is accepted: should be made blank
- Domains to relay mail for: should be made blank
- Machines to relay mail for: should be made blank
- Keep num,ber of DNS-queries minimal (Dial-on-Demand): No
- Delivery method for local mail: mbox format in /var/mail/
- Split configuration into small files? No
This is just an example. Mail should be configured however the site needs. The CMS just expects to be able send outgoing email.