<div>
1) Have you looked at event viewer for any clues regarding this error?<br />
2) Have you run Windows updates for MS office?<br />
3) have you tried these solutions from Microsoft?<br />
<br />
<a href="https://support.microsoft.com/en-au/help/2984912/outlook-continually-prompts-for-your-password-when-you-try-to-connect" rel="ugc">https://support.microsoft.com/en-au/help/2984912/outlook-continually-prompts-for-your-password-when-you-try-to-connect</a><br />
<br />
<a href="https://support.microsoft.com/en-us/help/3126599/outlook-prompts-for-password-when-modern-authentication-is-enabled" rel="ugc">https://support.microsoft.com/en-us/help/3126599/outlook-prompts-for-password-when-modern-authentication-is-enabled</a>
</div>


<div>
Hi<br />
<br />
Are you using the same name space for 2016 as with your 2010 environment?<br />
<br />
Do you have your SSL cert and URLS updated on Exchange 2016?<br />
<br />
Authentication for IIS set correctly?<br />
<br />
Where are your DNS records pointing? To the 2010 servers or 2016?
</div>


<div>
I tried the regedit to create a key for AlwaysUseMSOAuthForAutoDis<wbr />cover but that tries now to logon through a Microsoft account and as this is a .local domain it has problems.<br />
<br />
I also tried the tool suggested in one of the solutions and that fond a autodiscovery issue with one of the accounts which I have yet to fix but that is not the cause of the login issue
</div>


<div>
Hi Edward, <br />
Same name space<br />
Yes SSL certs are installed, 2010 certs have just expired<br />
I believe Authentication for IIS is set correctly but what is correct<br />
The DNS Records are now pointing to 2010 but changed a few hours ago from 2016
</div>


<div>
<div class="content wysiwyg-content">
After Migrating Exch2016 from SBS2011 (Exch2010) I have some issues.<br />
1. Outlook 2016 continually asks for PW and is disconnected<br />
2. mobile email on Android will not connect to server.<br />
<br />
Prior to Migrating some mailboxes and setting up internet facing on Exch2016 all seemed to be working OK,<br />
Outlook 2013 connecting to non Exch2016 mailboxes is OK (have not tried connecting to Exch2016 mailboxes)<br />
OWA works on Edge on Exch2016 for the 2016 mailboxes<br />
<br />
I have removed internet facing settings from Exch2016 and returned them to Exch2010<br />
<a href="https://filedb.experts-exchange.com/incoming/2019/03_w11/1414699/Exch2016Migration.txt" target="_blank" class="file-inline" title="Responses to PS Interigation (11 KB)"><svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><path d="M67.508 468.467c-58.005-58.013-58.016-151.92 0-209.943l225.011-225.04c44.643-44.645 117.279-44.645 161.92 0 44.743 44.749 44.753 117.186 0 161.944l-189.465 189.49c-31.41 31.413-82.518 31.412-113.926.001-31.479-31.482-31.49-82.453 0-113.944L311.51 110.491c4.687-4.687 12.286-4.687 16.972 0l16.967 16.971c4.685 4.686 4.685 12.283 0 16.969L184.983 304.917c-12.724 12.724-12.73 33.328 0 46.058 12.696 12.697 33.356 12.699 46.054-.001l189.465-189.489c25.987-25.989 25.994-68.06.001-94.056-25.931-25.934-68.119-25.932-94.049 0l-225.01 225.039c-39.249 39.252-39.258 102.795-.001 142.057 39.285 39.29 102.885 39.287 142.162-.028A739446.174 739446.174 0 0 1 439.497 238.49c4.686-4.687 12.282-4.684 16.969.004l16.967 16.971c4.685 4.686 4.689 12.279.004 16.965a755654.128 755654.128 0 0 0-195.881 195.996c-58.034 58.092-152.004 58.093-210.048.041z"/></svg>Exch2016Migration.txt</a>
</div>
</div>


Exch2016Migration.txt

After Migrating Exch2016 from SBS2011 (Exch2010) I have some issues.
1. Outlook 2016 continually asks for PW and is disconnected
2. mobile email on Android will not connect to server.

Prior to Migrating some mailboxes and setting up internet facing on Exch2016 all seemed to be working OK,
Outlook 2013 connecting to non Exch2016 mailboxes is OK (have not tried connecting to Exch2016 mailboxes)
OWA works on Edge on Exch2016 for the 2016 mailboxes

I have removed internet facing settings from Exch2016 and returned them to Exch2010

Exch 2010 to 2016 Migration Outlook 2016  and mobile devices not connecting

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.

Exchange

Microsoft Outlook is a personal information manager from Microsoft, available as a part of the Microsoft Office suite. Although often used mainly as an email application, it also includes a calendar, task manager, contact manager, note-taker, journal, and web browser.

Outlook

Mobile web development, also known as responsive web design, is an approach to web design aimed at crafting sites to provide an optimal viewing and interaction experience—easy reading and navigation with a minimum of resizing, panning, and scrolling—across a wide range of devices (from desktop computer monitors to mobile phones). A site designed with RWD adapts the layout to the viewing environment by using fluid, proportion-based grids, flexible images, and CSS3 media queries.

Mobile

Android is a mobile operating system developed by Google, based on the Linux kernel and designed primarily for touchscreen mobile devices such as smartphones and tablets. Android's user interface is based on direct manipulation, using touch gestures that loosely correspond to real-world actions, such as swiping, tapping and pinching, to manipulate on-screen objects, along with a virtual keyboard for text input. In addition to touchscreen devices, variants of Android are also used on notebooks, game consoles, digital cameras, televisions, automobiles and other electronics. Applications are usually developed in Java programming language using the Android software development kit (SDK), but other development environments are also available, including Delphi, Ruby and Visual Studio (using C++).