Can someone clarify the following instruction given on CiC website regarding mailing of immigration application
Mailing instruction
Put the completed forms, supporting documents required for your sponsor in a 23 cm x 30.5 cm (9″ x 12″) envelope.
Send your completed application to your sponsor’s Canadian address.
Does the abovementioned mean the immigration application from spouse and supporting documents should be mailed to sponsor in a sealed envelope which cannot be checked by sponsor for accuracy and completeness and has to be forwarded to CPC in the same condition?
Mailing instruction
Put the completed forms, supporting documents required for your sponsor in a 23 cm x 30.5 cm (9″ x 12″) envelope.
Send your completed application to your sponsor’s Canadian address.
Does the abovementioned mean the immigration application from spouse and supporting documents should be mailed to sponsor in a sealed envelope which cannot be checked by sponsor for accuracy and completeness and has to be forwarded to CPC in the same condition?
so just prepare everything from your side, send it to your sponsor, he/she will add the documents needed, and sometimes the "proofs of genuine relationship" go in a 3rd envelop.... try and follow the checklists provided by CIC to make it easier. 
