I had the same problem, and used the same solution. The same program works everywhere else, but not on this one computer that has the exact same Outlook settings. "Open Automation" returns an error -2147319765 saying "Element not found.
in send_outlook_mail_activex.vi". Outlook works fine by itself, and can even work from word file with VBA.
Did the Office365 repair as mentioned above. Immediately after the repair is done, the program still does not work. Rebooted the computer, now the program works. First time running, Outlook pops a message saying "a program would like to send message on your behalf, would you like to continue", agree and then email is sent out. Afterwards everything is normal.
Seems sometimes there is something wrong with 365/outlook installation that Labview happens to be sensitive to.
