Do not respond to unwanted texts or emails from questionable sources. Several mobile service providers will allow you to report unwanted spam texts by simply texting/forwarding it to 7726 (or “spam”) to enable the providers to prevent future unwanted texts from the specific sender.

(If your provider is ATT, try the code "block")

Source:
http://www.fcc.gov/guides/spam-unwanted-text-messages-and-email

More info:
http://en.wikipedia.org/wiki/Mobile_phone_spam
http://blog.usa.gov/post/89152807112/protect-yourself-from-text-message-spam

However, in many cases, the text origin, as seen on your phone, is faked.  The internet domain does not exist, or the phone number may have been spoofed.

  Got this email message from jennica86bk1@aol.com saying that I answered a post she had made and wanted to know if I was interested in meeting for some fun...She left this no# 415-853-4844 to call her. This is obviously a scam so I didn't bother replying instead I just posted it here for others to see.

Below is the email I received, I'm not going to attempt any contact, neither should you...

From: qtfelizamo4@aol.com

Subject: Just wantin to tell you something
Whatsup Babe

So I think You and me would have a lot of fuuun 2gether. Im definitely not looking for Mr Right, just somebody to connect with.

I don't have time for anything long-term really, but I am always up for a movie and some bedroom fun after if that floats your boat.

So let's see how things end up, and start by trading a couple pictures.

You can send me a Text message on 415-853-4844 - Im really lookin fwd to it!

I got this in an email reply to a Craigslist ad I posted.  Obviously I did not respond:

Hey,
Saw yer ad... I am interested... 26-F here. Do u have a cell so we can swap some pix..
We should see how things go on the phhne first... Why dont ya teexxt me.. Numbr is 415<853<4844

A scam don't Fall for it