Question about Outlook Express

For the last few days (and 4 times within half an hour last night) I have been receiving text messages from different phone numbers, all with the message "Microsoft Support Code:" followed by a 6-digit number (each time different). I have not requested any support codes, nor have I been having any trouble with my account that I'm aware of. Is this just some sort of scam, or could there be a problem with my account that I'm not aware of? I have tried doing an internet search of the phone numbers, just out of curiosity, but with no results.