Having problems with Office and Outlook for Mac 2016 (Sept/Oct 2017)   We have multiple email accounts using Mac OS with Microsoft Hosted Exchange and Apple Mail and had recently been experiencing two errors for the last few weeks. Each time Outlook is opened, the password for each Exchange account was requested “You’re connected to too many services. Please remove some connections before adding additional services” is displayed many times in Office programs. After a lot of research and much trial and error, we solved the issues. Here is what we did.   Step A – Clean up your Keychain Close ALL Office for Mac programs fully. Use “Force-Quit” to make sure they are all fully closed before cleaning up your keychain. 1. Go to KeyChain Access.(this can be done using spotlight search) 2. Search “Exchange” under Login –> All Items and delete everything. 3. Search “Office” and delete everything. 4. Search “ADAL” and delete everything. 5. Repeat for “Outlook” and delete everything. 6. Close Keychain Step B – Cleanup Open Services When you have more than one Exchange account in Outlook for Mac, you need to clear up multiple open accounts such as multiple “OneDrive” and “Sharepoint” accounts. Open Excel or Word. If you see multiple accounts like the following, remove all accounts except the main one, by hitting the “minus” or delete key Sign Out Sign back into the main account. Repeat the above steps if necessary. Now open Outlook, add the passwords for each account one more time, you should not be prompted again. See Also https://answers.microsoft.com/en-us/msoffice/forum/msoffice_outlook-mso_mac/authentication-failedcheck-your-account/063826c1-1e4c-40ba-9bfa-54e745925fc1 https://answers.microsoft.com/en-us/msoffice/forum/msoffice_outlook-mso_mac-mso_mac2016/problem-with-outlook-mails-in-mac/b24fa623-d306-4c6b-80a8-909e72425e82 Microsoft Office: You’re Connected to Too Many Services :jk: