Problems with sending BBC mail to a group. Using windows live mail

Hello,

I sent an email out to a number of my contacts, BBC ing the group in as I normally have done. Once I looked at the send mail I saw that it have was only sent out to about 20% of the contacts that I have added.

I had BBC ed about 5 different groups and it seemed to send to a randon selection of emails from varios groups.

Any ideas why this happened? I have done it in the passed and it worked fine.

Thank you in advance.

Bret