To notify IRCC of changes to your application, visit http://www.cic.gc.ca/english/contacts/web-form.asp, click the “Tell us more” button, select “Hong Kong” as the visa office where you sent your application and follow the submission instructions. 这个是我邮件里关于联系IRCC的提示,如果你是Mississauga,那属于加拿大境内,所以在点击“TELL US MORE”以后“Is your application being processed by an office OUTSIDE Canada?” 里选择"NO",下一个页面就可以写邮件联系了。