If autodiscover records aren't published, your administrator will need to publish them so Outlook can find the account. If you want to use Outlook 2016 with an Exchange account, you'll need to let Outlook set the account up automatically.From Tech Net's What's new for administrators in Outlook 2016 for Windows: Exchange connectivity settings are now retrieved directly from Auto Discover instead of the registry, making profiles more reliable.To solve this problem, you can empty the cache in Outlook so that Outlook can download all the items from your Exchange account again.Caution: The following procedure deletes any information that is not synchronized with the Exchange server, including your contacts' mail certificate.There two options: add domains and addresses to the safe or blocked lists in Exchange admin center or to Outlook using powershell.
We have a forum article discussed this issue in detail, please follow the instructions in the article to troubleshoot the issue: https://social.technet.microsoft.com/Forums/en-US/bcd2d9c2-1a1b-4446-bf32-69fee8cdf11b/why-does-outlook-keep-prompting-for-password? Regards, Steve Fan Tech Net Community Support Microsoft is conducting an online survey to understand your opinion of the Technet Web site.
Thanks to Exchange Active Sync technology added since Microsoft Exchange server 2003, all synced devices can exchange data in a manner that prevents deleting, duplicating or corrupting data.
You can use this technology with any version of Outlook (2003, 2007, 2010, 20) as well as with any i Phone, including i Phone 5/5s, i Phone 6/6s/Plus and i Phone 7.
If you successfully connected to the account before, try to connect to it from another Exchange application, such as Outlook on the Web.
You can also check the status of the Exchange server by contacting your Exchange server administrator.