With the 1709 Creator Update or later update for Windows 10 applied, Excel 2016 starts throwing a ‘General Mail Failure. Quit Microsoft Excel, Restart The Mail System And Try Again’ error message.
- Close Outlook and Excel
- Delete (or rename) the file msmapi32.dll from C:\Program Files (x86)\Common Files\System\MSMAPI\xxxx where xxxx is a language code of your Office installation. NOTE: U.S.A. is typically 1033.
- Restart Outlook and Excel
- You should now be able to send email like normal from Excel 2016. The MSMAPI32.DLL will automatically re-appear in the folder above.