Outlook 2016 prompting for password

goliveuk used Ask the Experts™

I am at a process of migration SBS 2008 with Exchange 2007 SP3 to Server 2012 R2 with Exchange 2013. At later stage I will remove the SBS and will upgrade the Exchange server to 2016.

*The exchange server is running on Server 2012 R2, and there is a second domain controller - also Server 2012 R2.

However at the moment, I have the following issue:

 - Outlook 2010 started to prompt for password after the mailbox is migrated to the new exchange server (using cache mode) - this was fixed by changing the security settings for the account to use Password authentication (NTLM).
- If I upgrade to Office 2016 the Outlook prompts again for password in cache mode - in online mode everything is working fine.

All workstations are running Windows 10 Pro

What I tried so far:

1. Clearing all credentials in credentials manager.
2. Recreating Outlook profiles.
3. Clearing all credentials in credentials manager, rebooting the computer and recreating Outlook profile.
4. Adding registry fix to disable the auto discovery for Office 365.

Thank you for all you replies in advance :)
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Gaurav SinghSolutions Architect

can you please let us know if HttpMaPI is enabled?


Hi Gaurav Singh,

I checked the mailbox that I am testing with, and it confirms that MAPI is enabled for it.


Hello everyone,

I believe I found what the issue was. When I did: Get-OutlookAnywhere | fl    I noticed that the first result was from the old exchange server , and it was  missing this: InternalClientAuthenticationMethod : Ntlm. I enabled NTLM auth on the old server, and everything is working fine now.

RunspaceId                       : 33332e38-55dc-4c26-b8f8-3c4a0ef6ea38
ServerName                       : SERVER
SSLOffloading                     : False
ExternalHostname                 : remote.clientdomain.com
InternalHostname                 :
ExternalClientAuthenticationMethod : Basic
InternalClientAuthenticationMethod : Ntlm
IISAuthenticationMethods         : {Basic}
XropUrl                           :
ExternalClientsRequireSsl         : True
InternalClientsRequireSsl         : False
MetabasePath                     : IIS://SERVER.pr.local/W3SVC/3/ROOT/Rpc
Path                             : C:\Windows\System32\RpcProxy
ExtendedProtectionTokenChecking   : None
ExtendedProtectionFlags           : {}
ExtendedProtectionSPNList         : {}
AdminDisplayVersion               : Version 8.3 (Build 83.6)
Server                           : SERVER
AdminDisplayName                 :
ExchangeVersion                   : 0.1 (8.0.535.0)
Name                             : Rpc (SBS Web Applications)
DistinguishedName                 : CN=Rpc (SBS Web
                                    Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=First
                                    Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=pr,DC=local
Identity                         : SERVER\Rpc (SBS Web Applications)
Guid                             : 0f415c8c-7e77-47a4-a46e-5faa9795685d
ObjectCategory                   : pr.local/Configuration/Schema/ms-Exch-Rpc-Http-Virtual-Directory
ObjectClass                       : {top, msExchVirtualDirectory, msExchRpcHttpVirtualDirectory}
WhenChanged                       : 5/25/2018 1:28:35 PM
WhenCreated                       : 10/2/2014 1:53:05 PM
WhenChangedUTC                   : 5/25/2018 12:28:35 PM
WhenCreatedUTC                   : 10/2/2014 12:53:05 PM
OrganizationId                   :
OriginatingServer                 : DC.pr.local
IsValid                           : True
ObjectState                       : Changed

RunspaceId                       : 33332e38-55dc-4c26-b8f8-3c4a0ef6ea38
ServerName                       : EXCHANGE
SSLOffloading                     : True
ExternalHostname                 : exchange.clientdomain.com
InternalHostname                 : exchange. clientdomain.com
ExternalClientAuthenticationMethod : Ntlm
InternalClientAuthenticationMethod : Ntlm
IISAuthenticationMethods         : {Basic, Ntlm, Negotiate}

Thank you everyone for the help. I am now able to proceed and look forward for removing the old SBS :)

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