I wouldn’t say its a red flag and to stop all dealings, but just to be more careful.

It is common for suppliers to ask people their personal details to get in contact more efficiently, as Alibaba is a exchange platform which incurs costs to the seller - be it through a transaction, SEO keywords, or currency exchange. Plus, it makes communication more instantaneous and easier.

Now, here are some pointers:

a. If you are offered a price that is well below the market price or the selling price of various suppliers (always pays to shop around), then it could be a scam. Check with other suppliers or sites.

b. See if the e-mail address is the same one listed on the Alibaba site. Do a quick search of the e-mail address on Google to see if any “red-flags” show up.

c. Do not commit to any payments early on. Gauge the nature of the conversation in terms of response rate, knowledge of product, pricing ratios, general outlook. I would say trust your gut if you are overseas (first), or call a Chinese agent (trading companies) to get security - you might incur additional charges (later).

d. Ask them for their WeChat /QQ/ Phone just to see if they can give you more information about themselves. Obviously a recently created WeChat account is a red flag or a overseas number for that matter.

The overall conclusion is: Its normal, but be careful. They are scammers, but there are many real suppliers on Alibaba as well. Do not commit to anything early on and do your side of due diligence before entering in any sort of financial activity - just so you don’t get duped.