It requires so many things to align perfectly in order to work properly with an email account. This is why you’ll find your Microsoft 365 (formerly Office 365) signature not working correctly and displaying images in a way you didn’t intend. Then, you can try to use this function to see whether it is normal. To download and install the Microsoft Support and Recovery Assistant, click download the tool. There may several factors that can interrupt the normal working procedure of Outlook for Mac. Outlook has one Online mode but two offline modes: Exchange Cached mode and Offline Folders. While this issue has been isolated in the preliminary check, we could discuss it here. Test the user name and password by logging on to Outlook on the web, and try to send a test email to make sure the account is not blocked. IMAP Synchronization Issues in Outlook 2013 and Office 365. To unblock it, you can just send an authentication code to your phone number and verify it on Outlook.
You have an option of buying Office 365 OR do not waste your time and energy on this issue any more, it simply : 1.83 Fixed to work with the latest versions of Mozilla Thunderbird.