I am trying to move all my folders out of my outlook:mac version 14.3.9  (on my computer) either to Gmail, mac Mail  or an Imap account so if something happens to my computer my files are always backed up.

I moved to Mac from PC (regular Outlook) in 2012 generating the PST file and importing it into outlook mac.  i have been working fine with it until now. 

the problem is when moving the folders to Gmail, Mail or the Imap account all emails from before 2012 (that originated from the PST file) become unreadable and some of them  start the first lines with something like aner-ReportURL: https://mailcleaner/rs.php

the emails after 2012 (that were actually received/sent on outlook:mac) pass onto the other account just fine.  

I have years of files and work that I cannot afford to loose.

any suggestions?? please HELP!!!!