Which courier company is the best to send app

[Aspiring Canadian]

Which courier company should I use. Fed ex ? Is express post from Canada post still a courier? I want to be able to see that it was delivered and received

 

[Lex2019]

Anyone is good as long as there's tracking

 

[Aspiring Canadian]

do we need to write anything other than the address outside the envelope addressed to IRCC like our name or something