This computer developed a problem where it could not send or receive email via MS outlook. I ran every anti-virus program I could find: MS MRT, BitDefender, MalWare Bytes, and SpyBot just to name a few of them. I un-installed and reinstalled MS Office. I nuked the PST file and created a new one. All of this to no avail. After two days of working on the computer I discovered an obscure setting in MS Outlook that was blocking all email. It is found under Options, advanced options, add-in manager. Something called 'Redemption Center Outlook Extension' was installed. How reinstalling Office could not fix this I do not know. That's the problem with reinstalling MS Software, it leaves a lot of junk behind that reappears when you reinstall it!