Thanks for that.
Yes it seems to work.
Also if you go to contacts and select your group whilst holding down control, it offers you the choice to either export group as a vcard or send an email.
Select send an email and the group list is secure.
With both options the end result is the same.
Except that with the control click option you can only send to one group at a time.
Each control click generates a new email.
Guess you could cut and paste from one email to another.
With both options the usual blue oval surrounding the group name dissappears in both cases.