Many sellers do not use tracking because it is very expensive.
For example if I send a 400 gram paperback book to Ontario by untracked LetterMail it would cost $5.05, but by tracked post it would be around $12.
Don't worry the postal system is very reliable.
It takes about 10-15 for arrival from Europe.
It takes about 15-20 days for arrival from North America
It takes about 20-30 days for arrival from Asia.
So anything you bought before December 5th is unlikely to arrive in time for Christmas. Actually Canada Post usually gives November 15 or so as the last date for shipping outside Canada for Christmas arrival.
If that is the question, plan to buy locally for holiday presents.
If your item has not arrived within 30 days, you should contact the seller as a first step.
You have up to 45 days to open a Dispute for Item Not Delivered, don't let it go past Day 40 though. Mark your calendar.
