Suspect email offer

This afternoon, I received an email with all the Virgin Media typeface and logos stating that they notice I've got an older hub and offering a Hub 4 at no cost. 

Alarm bells rang... I'm being offered something for free and I don't even have to upgrade or sign a new contract with 4 months left on my current package? Yeah right! 

I checked the email behind the header and it was email@em.virginmedia.com so was weary of the em. Before virgin media. I did a quick online e search and this virgin community group seems to suggest it's real from a number of posts. A quick call to virgin tech dept and some checks and they said its spam and delete. 

More online checks and everyone says it's real. It states my name, but guess that could have been picked up somewhere. 

Thing is, if its real, firstly why use an email that raises concern with many, and secondly, how rubbish is it if virgin don't even know if their own emails are real? 

Any advice?