Outlook keeps asking for password… Using Office 365 but on-premise exchange?

Starting in Outlook 2016 version 16.0.6741.2017, Microsoft has enabled a new feature called Direct Connect to Office 365. What this feature does is connect Outlook directly to Office 365 if Autodiscover is not working. This is great feature but a network hiccup may cause your mailbox to connect to Office 365 rather than your on premise Exchange, even with a valid autodiscover record.

For Direct Connect to take effect the user must have an active mailbox on Office 365 with a valid license. Typically Direct Connect would be a neat feature unles you are in the middle of a migration to 365, but a network hiccup could incorrectly connect you to 365 even though you havent completed your migration yet.

During 365 migrations deom Hosted Exchange or On-Premise, we recommend disabling this option from the user computer registry:

You can stop Outlook from checking Office 365 for settings by setting a registry key.

DWORD: ExcludeExplicitO365Endpoint
Value = 1

Then restart your computer and it should stop trying to connect to Office 365. When you are ready to flip the switch on your migration, remove this registry key.

Heres a great article describing the whole thing in more detail…

Outlook 2010 signature button not working (64-bit)

I recently removed Office 2010 (32-bit) and installed the 64-bit version. This introduced the problem where my signatures in Outlook were no longer being added to emails.

I fully understand the process of creating signatures, how they work, where they are saved etc so off I went to File > Options > Mail > Signatures

My issue was that the “signature” button, when pressed, wouldn’t open the window with all the options for creating and editing signatures. Clicking it just did nothing!

After a bit of searching I found the following solution…

Use “regedit” to change the “(Default)” and “LocalServer32” values in each of the keys below to C:\Program Files\Microsoft Office\Office14\Outlook.exe




Once the keys have been changed, launch outlook and the signature button will work again allowing you to change your signature preferences.

Note: The above fix will also work for the 32-bit version of Outlook, just change the C:\Program Files\Microsoft Office\Office14\Outlook.exe to C:\Program Files (x86)\Microsoft Office\Office14\Outlook.exe