Special Outlook problem

Shortly after installing a new Office 2016 (Click to run) on a new Windows 10 PC, Outlook - already connected to an Exchange 2016 server in a domain - began to ask for user and password - although Outlook showed "Connected to Exchange" at the bottom of the window.
This happend a few seconds after Outlook was started, and one or the other time during the day.

For the first moment the Problem could be solved by clicking "Cancel" in the window that asked for the login credentials, and then by clicking on "Enter Password" at the bottom of the window - and Outlook was working for some Hours without further asking.

Fortunately I found this article (https://social.technet.microsoft.com/Forums/en-US/b57ee243-2545-4ad8-81a5-7c005e4cf6ec/outlook-2016-repeatedly-asks-for-password-and-none-of-the-fixes-i-have-found-are-working?forum=outlook), solving the Problem in my case, by adding an unexpected registry entry.

I had to add/find this key

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover
(16.0 corresponds to the Outlook version: 16.0 = Outlook 2016)

and add this new DWORD ExcludeExplicitO365Endpoint, and give it the value 1

And voila - after restarting Outlook the problem was gone :-) !

Helped me, and I hope it helps anyone else !

Outlook once more: Outlook does not allow to add new signatures

This problem appeared on a brand new installation of Outlook 2016 where the user was unable to add a new signature. After some searching and trying several other solutions this one fixed the problem, one more time a registry entry has to edited/added:

Find the following key in the registry, for 32-bit installation:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{0006F03A-0000-0000-C000-000000000046}\LocalServer32

For 64-bit installation it is:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Wow6432Node\CLSID\{0006F03A-0000-0000-C000-000000000046}\LocalServer32

In the right pane of the LocalServer32 key, for both registry strings (REG_SZ) named (Default) and LocalServer32 set their value:

For 32-bit Office installation of Outlook 2013 on 32-bit Windows and for 64-bit Office installation on 64-bit Windows:
C:\Program Files\Microsoft Office 15\root\Office 15\Outlook.exe

For 32-bit Office installed on 64-bit Windows:
C:\Program Files(x86)\Microsoft Office 15\root\Office 15\Outlook.exe

For Outlook 2016 replace number 15 above with 16 !

Good luck !

See also:
http://www.thewindowsclub.com/unable-to-add-signature-in-outlook


UPDATE 2019-09:

There is another known reason which can block the signature function on clients with Windows 10, the App "Microsoft Office Desktop Apps" can cause this problem. Uninstalling the App via the Windows Settings / Apps & Features can fix it - see also https://answers.microsoft.com/de-de/msoffice/forum/msoffice_outlook-mso_win10-mso_2016/outlook-2016-signaturen-briefpapier-%C3%B6ffnet/3b1439fc-2606-4306-b2d3-57a5ce440163

Show contact (link) in Outlook calendar entry, task, ...

Outlook has a nice feature called "Contact Linking" that allows you to link a contact with any appointment, task, other contacts, or even email. Adding this link is done with a button on the bottom of the appointment details.

In the new versions of Outlook (2013, 2016) this button is hidden by default, to reactivate it you have to change/add an entry in the registry, which are described here:

Outlook 2016:
HKEY_CURRENT_USER\​Software\​Microsoft\​office\​16.0\​outlook\​preferences

DWORD: showcontactfieldobsolete

Value = 1

Outlook 2013:
HKEY_CURRENT_USER\​Software\​Microsoft\​office\​15.0\​outlook\​preferences
DWORD: showcontactfieldobsolete
Value = 1

Find more details on this eg. on this page:
https://www.slipstick.com/outlook/contacts/show-contact-linking-fields/

Outlook always prompts for login credentials to Exchange

There are a lot of reasons why Outlook keeps asking for your password every time you start it, so that it can connect to an Exchange server.

In my case it was one of the rarely described problems, but if you know it, it is quite simple to solve. Windows (in this case it was Windows 7 as well as Windows 10, with Outlook 2010 as well as 2016 on an Exchange 2010, but probably it would be the same on 2013 or 2016) stored some of the old login credentials in the system and became confused.

You simply go to the Control panel, open the credential manager (maybe you have to change to "Windows login informations" like in Windows 10), and find some entries further down, one or more containing the word "Outlook". When you expand them you find a link to click and delete the entry. And voila, the problem - in my case - was solved !

Good luck !

And here is the original Microsoft posting on this:

https://support.microsoft.com/en-us/help/2762344/outlook-continues-to-prompt-for-credentials-after-your-domain-password

Can't find it in Outlook ...

Outlook ocassionally causes problems when we try to find something in the mass of mails which are mostly collected.
There are several reasons why this may happen, and I'll tell you about some solutions which worked for me in this situations:

• Rebuilding the search index
• Activating the indexing for Outlook which incidentelly was turned of
• Actication of indexing for datatypes msg, pst, ost
• Repair PST files with scanpst.exe and and compress them with the compression function of Outlook
• Repair your Office software using the function in your control panel / programs

The detailed information how to perform those actions can be found in a lot of websites in the internet, I hope one of them is the right solution for you :-)