Take note that Excel in-built protection aspect is not pretty sturdy and you'll easily open worksheets/workbooks that were locked. On the other hand, if you want to rapidly guard it prior to sending it towards your manager/customer (so that they don’t find yourself switching something by blunder), it works nicely. https://onenotetraining.sport.blog/2024/09/17/microsoft-outlook-a-comprehensive-guide-to-outlook-training/