SMTP Satellites
Other LAN Systems
SMTP Satellites
Why?
Systems inside our domain may not be an full MTA, but we still may want to allow them to send messages.
- i.e. Log messages from database machine to be sent to our email address
Run a very stripped down MTA on these hosts
They will send messages to mail server
Will not receive messages
Mail server relays for satellites
SMTP Satellites
SMTP Satellites
- Mail satellite MTA’s do NOT receive incoming messages.
- DNS directs mail traffic to mail server via MX records
- Mail server accepts incoming messages for satellite systems, storing them in users inbox.
SMTP Satellites Configuration Steps (Outgoing)
- On Satellite, install exim4, mailutils
- Configure exim4 to send through mailserver and NOT receive
- On mail server configure exim4 to RELAY for satellites
SMTP Satellites Configuration Steps (Incoming)
- On satellite, install exim4,
- configure NOT to receive
- On mail server, configure exim4 to treat satellite destinations as local
- On mail server configure exim4 to RECEIVE for satellites
- Configure DNS to have MX records for ALL satellite systems
- Configure DNS to have TXT spf records for ALL satellite systems
- Test!!!
Last Updated 08/09/2023