In my case, they sent my 1st and 2nd AOR thru email only. If you provided your email address when you filled out your application, they will use it to establish communication with you. This came with my 2nd AOR,"
Communication by email;
We will communicate with you by email if you have indicated an email address in your application or an enquiry. Therefore, please ensure that you provide us with a valid email address and that you check your email account regularly.
Consent & Disclaimer: By supplying your email address (in your enquiry or in your application), you are initiating an email communication with Citizenship and Immigration Canada (CIC), and CIC is thereby authorized to use the email address provided by you for communication with you including the transmission of personal information on your file/case. When you supply your email address to CIC, it is also understood that you are aware that this channel may not be a secure channel. CIC is not liable for the disclosure of personal information to a third party where CIC has taken reasonable means to ensure the identity of the party. CIC is also not liable for the misuse of this information by a third party. " Hope this helps.