Have you received your acknowledgement of receipt (AOR) letter or email? I mailed my application in September 2020 and received my temporary AOR a few days ago (April 2021).An Acknowledgment of Receipt (AOR) is an official letter that IRCC sends you confirming they have received your application and will start processing it. Receipt Number; A-Number (if applicable); Date when filed; Application or Petition filed; Item not received; Email Address.