Guys,
In case you are wondering why everybody gets this AOR email even when they have submitted documents or paid fee already, I have summarized a few reason that I can understand. Hope this helps to understand the process instead of cursing CIC for everything:
1. The rules for getting the PCC is different for different countries...so more than 200 such rules exist in CIC website. A few countries will not give you an upfront PCC (unlike India) and they will ask you to provide a proof that CIC has requested a PCC from you. In that case you need to provide this AOR letter to the police department of that country (example is Singapore).
2. You might be staying in multiple countries and it is possible that at the time of application you were staying in a foreign country for less than 6 months, but now the 6 months are over and now you need to provide the PCC for that country as well. If that is a case, than this reminder is for you.
3. They provide you an option to either chose to pay RPRF upfront or later. So in case you have not paid upfront, then this letter also serves the purpose to remind you to pay RPRF to avoid further delays. Instead of checking for everyone who has paid and who has not (which will take time for CIC), they just add a generic statement to this letter so that you can take action in case you have not paid already.
The email clearly mentions if not already paid or if not already submitted., in bold and underline. So I think it should not cause any confusion.