What can I do to stop the SPAM from Craigslist?

Stop responding to these emails - everyone gets them. No real buyer would say is the "item" still for sale. They would say "I'm interested in your iPhone, laptop, diamond ring, mountain bike" or whatever else you specifically listed - the fact they say "item" means they are a scammer sending these same emails to anyone who lists anything for sale. Also check the IP address of these emails before you respond - most of the scammers will show up that they are from Nigeria or another foreign country, and most don't bother going through a proxy server on Craiglist scams

Also make sure your ad says something like "No Shipping" and "Cash Only" - and only deal with people you can meet in person, like at a McDonalds or Starbucks or other public place, and exchange the item for cash. If you stick with that, you'll be safe. But you will still get tons of spam - that's just part of it. Craigslist has no control over who responds to your ads.

I just got spam on craig'slist. I put an ad and the person took my ad, my information and did another ad, but actually sold my item for less than I posted. My problem is that this person probably has my personal information. Lesson learned. Don't ever put your number on craig'slist.

Now I have to change everything...it wasn't worth the money of the item i sold....

You can't stop it. It is part of using a free service like CL. You can put in the body of your ad: "Please write the words "no spam" in the Subject Line when you respond to this ad. If you don't write those words, i won't open your email." Those are not real people cheating on their spouses. They are "bots" that are set up to reply to 1,000 CL ads every day. You can also elect not to have the email address. Post your phone number. That can cause problems if the people respond with text messages that you have to pay for.

They are spam, so treat them as spam. However, since they are from a place you do not want to stop getting mail from, you do not want to mark them as 'spam!" So as soon as you see one, just delete it straight into oblivion.

Sell the item on ebay instead? Those Nigerian lottery scammers have become sophisticated in recent years.