I did an upgrade for one of my colleague to Windows 10 and use Office 2010 for her emails. She came to me reporting about this error:
Your message did not reach some or all of the intended recipients.
Sent: 20/10/2015 15:00
The following recipient(s) cannot be reached:
'*****@gmail.com' on 20/10/2015 15:00
This email message was not sent because we were unable to convert the message into Internet format (MIME). Removing attachments or removing forwarded text from the message may enable you to send the message. See http://support.google.com/a/bin/answer.py?answer=2392524 for details.
I followed the instruction as described by Google Support, to uninstall Google Apps Sync and MS Office altogether but error still exist.
To Run SFC /SCANNOW Command in Windows 10
Make sure you run the Command Prompt as Administrtor.
Type the command, SFC /SCANNOW
It will take a while and may report corrupt files detected but unable to repair. Don't worry about that.
Open your Outlook and try sending email, it should work now.