I have created a category with 160 emails in it for periodic group mailings.  I put the category in the bcc.  When I click on the "+" sign next to the category name, not all of the 160 are there.  Each time I try it, the number varies and the ones that appear in the bcc list are random.  Why won't all 160 names appear?  Do I have to break it up in much smaller groups?  I didn't have this issue in Outlook Express (my legacy working software).  What do I need to do to get a working mailing list?