We need to install exim4 to enable outgoing email

# apt-get install -y exim4

# dpkg-reconfigure exim4-config

Configure mail as appropriate for your site and IT infrastructure. We outline a sample standalone configuration below. The requirement is for php to be able to send mail (registration confirmation and other notices need to go out) and for exim4 to receive mail (for support ticket and forum email gateway functions to work).

This is just an example of a standalone mail configuration.

General type of mail configuration

internet site; mail is sent and received directly using SMTP

Mail name

enter the fully qualified domain name (FQDN) of the host (example.com)

IP-addresses to listen on for incoming SMTP connections

leave blank (listen for connections on all available network interfaces)

Other destinations for which mail is accepted

leave blank or (equivalently) with local hostname (all local domains will be treated identically)

Domains to relay mail for

leave blank

Machines to relay mail for

leave blank

Keep number of DNS-queries minimal (Dial-on-Demand)

No

Delivery method for local mail

mbox format in /var/mail/

Split configuration into small files?

Yes

Use a real email address below so you can see if you get the email

# Mail -v someone@gmail.com

Depeneding on your environment, you might want to route outgoing email on your hub through a third party. This often helps your hub's email look less like SPAM to many automated third party SPAM checking tools.