Configure postfix as a backup for Exchange


  • I want to use postfix on a virtual server as a backup in case my Exchange is down. Postfix should accept every mail and deliver it to the Exchange server instantly or wait until the Exchange server is available.


  • Existing postfix installation
  • Existing Exchange installation

Step 1

  • Login to your virtual server via ssh.

Step 2

  • Create and open the file /etc/postfix/transport
  • Insert for every domain you want to relay on its own line.
  • Run postmap /etc/postfix/transport

Step 3

  • Edit /etc/postfix/
  • Insert relay_domains = If you want multiple domains, separate them with a space.
  • Insert transport_maps = hash:/etc/postfix/transport
  • Run /etc/init.d/postfix reload
  • tutorial/mail/postfixredir.txt
  • Last modified: 2018-06-03 14:10
  • (external edit)