Thanks. In my case, my dependents are in the US and was requested to send their passports to a PO Box. I requested IRCC for an aternative send to address but they responded with instructions on how to create the return label. I requested again from them so I will see. I can infer that the address is the same as the ship from address but I want to get it from them in writing. Anyway, if I don't get a resolution from them then I will send it to the address for sending from within Canada when I'm in Canada later this month.