Spammers are finding more ingenious (or so they hope) methods for verifying email addresses and identifying email addresses used in contact forms. The latest method is to ask questions which either have some relevance to your website/blog or none at all. The lazy spammers just use the same ‘questions’ regardless of relevance. Those are easiest to spot, especially when you receive many in succession. The creative ones at least make an effort to convince you that they’re legit — but beware, because they’re usually anything but.
Another ploy to verify your email address is for spammers to respond to Craigslist postings, particularly if you’re selling something or seeking employment. Most people posting on Craigslist opt to use an anonymous email generated by Craigslist. This is a problem for spammers mining email addresses. So they respond to your ad asking if you’re interested in a job or if the item you’re selling is still for sale. What they want is to engage you so that you’ll reveal your actual email address. Once they get an initial response from you, spammers can use any email application in order to scan the exchange between mail servers to locate your true email address.
But how do you know for sure that these are spammers? Well, you don’t — at least, not for sure. It’s best to create a junk email address, maybe with Yahoo or Gmail, and use those to respond to such random, questionable inquiries. This way, you can separate the wheat from the chaff without losing a legitimate inquiry.