Free upgrade offer - Bogus or not?

Hi,

 

I've just received an un-solicited offer fron Symantec to update from Internet Security 2009 to Internet Security 2010 FOR FREE!

 

Now, no-one gives anything away for nothing and we've all been warned about trusting e-mails from banks and such.

 

I would like to know if this is a genuine offer or it's a trap from someone pretending to be Symantec.

 

Thanks for any help you guys can give me.

 

Jackie