For several years I have made quarterly mailings to several large groups, using group names in ththe e address book and sending the emails to the groups using Bcc mail option. Most recently I have been using Thunderbird as my Email client. Last quarter when I made my mailings, everyon'e address was published on each email sent. I have tried everything I know and that has been suggested by the Thunderbird support group, but have been unable to get the Bcc to suppress addresses. Yesterday, I switch everything over the em Client and have now tested the mailing again, using em Client address book and software, the same problem is occurring. Everything is being sent through .MSN server. Is it possible the problem is in Vista? And if so what should I look at?