Let’s have a quick glance at those factors. Besides this, there are many reasons due to which users get these Outlook Mac sync errors. Generally, Mac Outlook not syncing with Exchange Server issue occurs when Outlook’s connection with the Exchange Server is disrupted or the Outlook database is corrupted. Additionally, we will provide you a step-by-step guide to fix this issue in Outlook 2019, 2016, 2019. Summary: In this guide, you will know the reasons why Outlook for mac not syncing with Exchange Server issue occur.