Beware of your buyer. They will destroy your item, then claim it was sent that way. Poshmark will side with the buyer.

No, it is not. It's a reputable site. Make sure someone is active in their closet though, by checking when they last shared their items, or when they were last active by looking at their "meet the posher" page. I always ask questions before buying any thing. It's the best way to protect yourself from accidentally purchasing from someone who may not be active on their account. I have seen some people ship same day, next day or 7 days later — sometimes you have to wait for something if you really want it. You can check seller stats to make sure that you're going to be getting your item in a reasonable amount of time. Doing research on a seller isn't a bad idea. I always ask, "hello, is this item available?" Sometimes people comment back and some times people don't. I'll look when someone was last active in their closet before I make a purchase. There's been only one time I never received an item, and I cancelled after 7 days.

I've had a lot of luck with Poshmark. I've only been scammed once but that hasn't stopped me from using poshmark. I no longer trade due to being scammed. I follow all poshmark rule's. I've bought and sold on poshmark.
I once bought a watch, it looked like a really good watch. When I got it, I took it out of the packaging and it broke when I put it on. I contacted poshmark and I was able to return the watch and get my money back. Never dealt with that seller again. It was just a process waiting for answers because PoshMark decides if the product in question was described as you got it. They ask for pictures of proof.
My other experience was I traded with a girl. I tracked my package, I know she got it because it was delivered. She sent me a receipt from the PO saying she shipped out my package (We shipped the same day). She cut off half the tracking number, when I asked her to take a picture of the whole tracking number she claimed she had already threw away her receipt. She never shipped out the package. I was completely out of an item I could have sold.
Advice, follow posh rules. Do not trade. Read the "love notes received" section on the seller you wish to purchase from. Happy customers? More than likely you'll have a good experience. You can't fake "love notes" on posh.

Poshmark is a big joke. I was scammed and its really pathetic since they don't even follow there own rules. I prefer vinted because I made over $3000 selling old clothes and there the best. Stay away from Poshmark since its easy to be scammed and people sell clothes from China and steal pictures sell knockoffs which is illegal.