A disturbing experience made me question whether this wildly popular shopping website is really safe

Selling used clothes online can be highly lucrative; but as I learned recently, it can also lead to some creepy encounters.

I wasn't even remotely concerned about my safety when I joined the popular resale website Poshmark a couple weeks ago.

Several friends had encouraged me to join after raving about the sales they were making. One co-worker of mine said she earned more than $700 over the course of a couple weeks.

So I cleaned out my closet and posted photos of several dresses and blouses to the website. A couple weeks went by without any offers.

Then on April 30, I got a message from someone posing as a woman whom I'll call Stephanie. It seemed like a pretty normal inquiry - she wanted to know if the dress had been washed and how many times it had been worn.

But her next couple messages raised some red flags.

She asked me to refrain from cleaning the dress if it hadn't already been cleaned. Then she asked me to describe all the times that I have worn the dress. I ignored the requests and over the following week, I received repeated offers and messages from her. I didn't answer any of them.

Here's a screenshot of our exchange:

I told a couple friends about the ordeal, and they advised me to report the user to Poshmark. They suspected that "Stephanie" wasn't who she claimed to be. I assumed she would move on if I ignored her.

So I was surprised get an email Monday from Poshmark saying that my dress was sold to Stephanie. She had offered to pay the full amount for the dress, so Poshmark completed the transaction and asked me to ship the dress to her.

But the buyer's name, which Poshmark provided for the shipping label, wasn't Stephanie. It was a man's name.

After a quick search, I found him on Facebook. At this point, I was thoroughly creeped out.

I immediately cancelled the order. Every Poshmark shipment has the seller's return address on the label - meaning that if I had shipped this order, this person would know my first and last name and where I live.

I have no idea what he planned to do with the dress or whether he posed any threat to me at all. But I'm so jarred by the experience that I'm not sure I'll use the website again.

As resale websites get increasingly popular, it's important for women to be aware that this can happen. I asked my friends if they realized their return addresses were on their Poshmark shipping labels and none of them had given that detail much notice.

Poshmark is the leader in a growing group of secondhand fashion websites, such as Tradesy, the RealReal, Twice, Vinted, Thredup, and Copious, where users can buy anything from Banana Republic blouses to Chanel handbags at massive discounts. The company says it completed more than 1.5 million transactions in 2013 and it's on track to generate $200 million in sales this year.

There are currently 700,000 registered sellers on the website and millions of shoppers, according to the company.

It appears that most women have had positive experiences with Poshmark, based on the reviews. The app has 4.5 out of 5 stars on iTunes.

When I told Poshmark about my experience, a company spokeswoman said they have a strict policy on harassment and suspicious activity.

"If a community member feels they are being harassed or sees any suspicious activity on the platform, we recommend they immediately report the incident and Poshmark has policies and procedures in place in order to take quick action to protect community members," she said. "We also have a digital fingerprint on every community member who joins the marketplace and anyone who is violating any of our guidelines including harassment will be restricted and unable to join the community again."