Expired

This means that the end date on the Recurring Payment has been met.

Inactive

The Recurring Payment Status is normally manually set to inactive by a user of Salesforce/Payments2Us.  This indicates that the payer no longer wishes to have payments taken out.  When setting this, you should will be required to Cancellation Reason

Suspended - Max retries exceeded

When the nightly Recurring Payment Processor runs and it finds that the it cannot successfully charge a card, then increments the number of "Retry Attempts" on the Recurring Payment Record.

Should the number for of "Retry Attempts" exceed the "Recurring Retry Attempts" on the related Payment Form, then the status will be automatically changed to "Suspended - Max retries exceeded".