On my old Computer with Widows 7 I never had any problem in setting up groups of Contacts in Windows Live Mail and send a mass email by just entering the Group Name.

I now have Windows 8.1 and it does not work. I set up a Group of Contacts as usual but when I try and send an email having entered the Group name as the recipient, the email refuses to go and I get a message asking me to enter a valid email Address. Most annoying as it means entering say a dozen email Addresses individually rather than just one.

Any suggestions how to solve this most appreciated.