Some scammers "harvest" email accounts. When you reply to their email, your reply shows your true email address. That's all they wanted. They sell them to spammers.
If the price of your tablet is truly attractive, you will get real buyers. CL is a place for bargain hunters. Not a place to get "top dollar" for tablets.
Honestly you should probably look at other outlets to sell it. There are sites that are dedicated to electronic sales. I would do something like that for what you have. Provide more info about your tablet if you haven't already.
I found the site (below) a while back, you might check them out.
I would have used them before, but have not had a device to sell on there.
Emailing back is really the only realistic way, assuming they didn't reply with a phone number included.
Be aware there are off shore scam artists offering to pay more than your asking price, paying with a check, perhaps asking you to pay some forwarding service which gets the cam artist the cash they were only after. ONLY sell to locals face to face to be safe from fraud.
Take a look at some of the groups in Facebook, there are a lot of buy and sell groups located there. Some just specialize in digital gadgets.
I use Facebook groups to advertise my home based business and have used them with some success.
Hope this helps.
Some one was probably just playing you or changed their mind. Sell it to the next person instead.
I posted a tablet to sell on Craigslist and when someone emails me to buy the tablet I reply to them but no one ever calls me or replies..how to I reply to them because emailing back is not working! Thanks!