Hey man. Here's how possession works in Canada. We have the 'Controlled Drugs and Substances Act' (CDSA). I dont have my copy here, but there are 4 or 5 Schedules (s). Different drugs are classed differently (again, these are just examples since I dont have my list here)
Schedule 1 - cannabis, cannabis resin, etc
Schedule 2 - cocaine, methamphetamine
Schedule 3 - lsd, psylocobin
schedule 4 - morphine, heroin, etc
schedule 5 - anabolic steroids
The offence for possesion is section 4(1) of the CDSA. And in the fine wording it says its an offence to possess Schedule 1,2,3,4 drugs. No where does it say that it is illegal to possess schedule 5 drugs.
The offences for trafficking/possession for the purpose of trafficking are under Section 5.
In here, it does indicate that it is an offence to possess all schedules of drugs for the purpose of trafficking.
A lot of it comes down to the Police' interpretation of the situation. You could have 5 vials of different things for 1 cycle. But if the officer is ignorant to steroids or if he's just a dickhead, he may charge you under Section 5. But most times, they are aware that possession is legal, and common sense would dictate that under 10 vials is for personal use. I've seen them take small amounts off people and were later ordered to return them, because seizing small amounts of steroids is technically theft by the Police, since it's not an offence to possess it. Ironic eh?
Hope this clears things up a bit for you. As for searching the mail, there are strict guidelines on when and how it can be done. I'll try to get a clear answer for you on the domestic shipping thing in the next few days. I've got a couple guys who work in those areas.