I would be interested about why you are looking at spam mail. Do you also read about septic systems and becoming a massage therapist or do you have an interest in drugs specifically?
From what I have seen in the news professional thieves use the internet to unload their goods so you might be buying stolen stuff. This is an updated version of selling it out of their trunk. If people buy stolen goods that only encourages thieves. You have to check your own ethics to decide where you stand on the issue-are you willing to be a part of crime that drives up the cost of what you buy legitimately.
Another situation may be that the online meds are past the effective dates. When drugs pass sell by dates, they are supposed to be destroyed but you can imagine a lot, especially outside the US might not be. So the drugs sold on line might have been degraded or if they had been stored inadequately there may be unknown chemical changes and maybe worthless or dangerous.
A third option may be that they may be counterfeit, manufactured with substitute ingredients. They may be “sugar” pills but more likely they will have ingredients that mimic the real thing because even criminal businessmen want repeat business. We see how this can work by looking at what is happening in China the last couple of years with the substitution of chemicals that react like protein when tested. First it was animals hurt and killed and now it’s people. The threat is there for anything you ingest if you don’t know how and where it was produced.
So beyond the ethical and safety issues, you have to consider why you feel the need to take drugs without medical supervision. Prescription drugs can have contraindications that could sicken or kill you otherwise they would be OTC. And finally if you are in possession of prescription drugs without a valid prescription, it may be a felony.
I hope I gave you something to think about.