I have Windows Live Mail version 2012 (build 16.4.3508.0205) running on Windows 8.1.  I have 4 email accounts downloading to this program, 2 Gmail accts and 2 earthlink accts.  All are pop accounts.  I am getting dual copies of some emails, but it is not consistent.  It does not happen on all emails but it does happen in all the different accounts on a seemingly random basis.  How do I stop this?