I recently sent out an e-mail to a group of individuals and several of them (hopefully not all) received multiple copies (about 11 duplicate copies) of the e-mail. On other occasions I have received multiple copies (usually 2-3) of e-mails, but I really didn't think about it much - I just deleted the extra copies. Any ideas as to why this occurs and what I can do to insure that it won't happen in the future?