To start Excel in safe mode, hold down the CTRL key while you start Excel. There are two ways to start Excel in safe mode: the CTRL key and command-line switches. If you want to manually open Microsoft Outlook without running any add-ins, you can open Microsoft Outlook in the safe mode easily.Starting Excel in safe mode prevents all Excel add-ins, toolbar customizations, and startup folders from loading when the program is started.

Right Click BLOCK OUTLOOK > Disable Rule (or Delete if you don't think you'll ever need it again). (Assuming you already closed it)3. Windows Key + R (to open Run Box) > type wf.msc and click ok. AND, blocking it with the firewall guarantees no inadvertent deselecting 'Work Offline.' You will see at the bottom right that Outlook is just 'disconnected.' The 'Work Offline' mode will not be enabled, but your Outlook will have no internet access.When you're done trying to salvage the career-ending email from going out, you can do the following to undo the outlook block.1.

Excel For Mac Safe Mode