If the plugin detects a matter code in the subject line, and the matter code is between pipe characters (e.g. Our Ref: |P20016GB|), you can use the Open Matter option to open the matter in Equinox in your internet browser. 

If you already have Equinox open, the matter will open in a separate browser tab.

If no matter code is detected, you'll see a message advising that the plugin was unable to find the matter.
Note: If the matter code isn't between pipe characters, no matter code will be detected.