Exchange Server Migration – From 2010 to 2016

A small company I am working for has a self-hosted Exchange Server 2010 running, and my job is to migrate this server to an Exchange server 2016, since the old one is out of support for quite a while now.

I know that Exchange 2016 and 2010 can co-exist, and since we cannot afford to loose our emails, I did some testing first. I created a dummy user on the old exchange server, created a migrate job and tried to access it (But the goal is to shutdown the old server after migration has been completed).

Mailflow (sending/receiving from/to external/internal emails – everything works!) is not the problem.

But I cannot get the outlook (2010) clients to work. Please note that we are using Outlook only internal – on a machine which is domain-joined, external access is (currently) not necessary. Whenever I add the dummy account to my outlook, everything works as it should – but as soon as I close outlook and open it again, Outlook cannot access the information store anymore. Accessing the dummy mail via the internal URL https://ex2016.domain.local/owa/ works perfectly.

When I check the connection status right after adding the dummy email account, it shows those mapi over http connections (as far as I know, this is the default access method since exchange 2013). I have executed the autodiscover test, it was successful.

There is a certificate warning, since currently this is the self-signed certificate from the installation. But I also tried replacing this with a certificate issued to a real domain name, but that did not make a difference. (Even though I changed the certificate and the url, Outlook still showed a certificate warning, and I have no idea why!)

But I doubt that the certificate problems are related to my client issues. During my web research, I found a bug that has been existent on exchange 2016 servers, where the authentication on the mapi virtual directory has not been enabled, which caused those client connections to fail. I checked that (I installed exchange 2016 CU21), microsoft obviously fixed that bug – at my installation, authentication already has been enabled.

I am really lost now. Any hint on what could be wrong is appreciated!

Updated Info

Thank you for your reply: Concerning Outlook Version, I double checked it, it should be supported.

Microsoft Outlook 2010 (14.0.7268.5000) SP2 MSO (14.0.7268.5000)

Concerning the certificate warning: It is the first warning (The security certificate was issued by a company you have not chosen to trust.). Thank you for the hint about install certificate, I didn't know about this possibility.

What is really weird, I clicked on install, chose to install it for the whole computer, and closed outlook. After I reopened Outlook, the issue as above showed, and after a minute, the same certificate warning showed again, even though I installed and clicked on trust previously. I repeated the step, this time for the local user, and after a second restart, everything started working!

Why did I have to install the certificate twice ? Outlook connects only to the default website (ex2016.domain.local:443) and not to the exchange backend (ex2016.domain.local:444) correct ?

Here is the result of the powershell script (I removed all references to the old exchange server)

Transcript started, output file is C:\log.txt
 C:\Windows\system32>
 
 
PS>Get-OabVirtualDirectory | fl Identity, server, *Auth*, InternalURL, ExternalURL

Identity                      : EX2016\OAB (Default Web Site)
Server                        : EX2016
BasicAuthentication           : False
WindowsAuthentication         : True
OAuthAuthentication           : True
InternalAuthenticationMethods : {WindowsIntegrated, OAuth}
ExternalAuthenticationMethods : {WindowsIntegrated, OAuth}
InternalUrl                   : https://ex2016.domain.local/OAB
ExternalUrl                   :



 C:\Windows\system32>
PS>Get-WebServicesVirtualDirectory | fl Identity, server, *Auth*, InternalURL, ExternalURL 

Identity                      : EX2016\EWS (Default Web Site)
Server                        : EX2016
CertificateAuthentication     :
InternalAuthenticationMethods : {Ntlm, WindowsIntegrated, WSSecurity, OAuth}
ExternalAuthenticationMethods : {Ntlm, WindowsIntegrated, WSSecurity, OAuth}
LiveIdNegotiateAuthentication :
WSSecurityAuthentication      : True
LiveIdBasicAuthentication     : False
BasicAuthentication           : False
DigestAuthentication          : False
WindowsAuthentication         : True
OAuthAuthentication           : True
AdfsAuthentication            : False
InternalUrl                   : https://ex2016.domain.local/EWS/Exchange.asmx
ExternalUrl                   :



 C:\Windows\system32>
PS>Get-OutlookAnywhere | fl Identity, server, *Auth*, InternalHostName, ExternalHostName


Identity                           : EX2016\Rpc (Default Web Site)
Server                             : EX2016
ExternalClientAuthenticationMethod : Negotiate
InternalClientAuthenticationMethod : Ntlm
IISAuthenticationMethods           : {Basic, Ntlm, Negotiate}
InternalHostname                   : ex2016.domain.local
ExternalHostname                   :



 C:\Windows\system32>
PS>Get-OwaVirtualDirectory | fl Identity, server, *Auth*, InternalURL, ExternalURL 

Identity                      : EX2016\owa (Default Web Site)
Server                        : EX2016
ClientAuthCleanupLevel        : High
InternalAuthenticationMethods : {Basic, Fba}
BasicAuthentication           : True
WindowsAuthentication         : True
DigestAuthentication          : False
FormsAuthentication           : True
LiveIdAuthentication          : False
AdfsAuthentication            : False
OAuthAuthentication           : False
ExternalAuthenticationMethods : {Fba}
InternalUrl                   : https://ex2016.domain.local/owa
ExternalUrl                   :



 C:\Windows\system32>
PS>Get-ClientAccessServer | fl Identity, Name, AutodiscoverServiceInternalUri

Identity                       : EX2016
Name                           : EX2016
AutoDiscoverServiceInternalUri : https://ex2016.domain.local/Autodiscover/Autodiscover.xml


 C:\Windows\system32>
PS>Get-EcpVirtualDirectory| fl Identity, server, *Auth*, InternalURL, ExternalURL

Identity                      : EX2016\ecp (Default Web Site)
Server                        : EX2016
InternalAuthenticationMethods : {Basic, Fba}
BasicAuthentication           : True
WindowsAuthentication         : True
DigestAuthentication          : False
FormsAuthentication           : True
LiveIdAuthentication          : False
AdfsAuthentication            : False
OAuthAuthentication           : False
ExternalAuthenticationMethods : {Fba}
InternalUrl                   : https://ex2016.domain.local/ecp
ExternalUrl                   :



 C:\Windows\system32>
PS>Get-ActiveSyncVirtualDirectory | fl Identity, server, *Auth*, InternalURL, ExternalURL


Identity                            : EX2016\Microsoft-Server-ActiveSync (Default Web Site)
Server                              : EX2016
MobileClientCertificateAuthorityURL :
BasicAuthEnabled                    : True
WindowsAuthEnabled                  : False
ClientCertAuth                      : Ignore
InternalAuthenticationMethods       : {}
ExternalAuthenticationMethods       : {}
InternalUrl                         : https://ex2016.domain.local/Microsoft-Server-ActiveSync
ExternalUrl                         :



 C:\Windows\system32>
PS>Get-MapiVirtualDirectory | fl Identity, server, *Auth*, InternalURL, ExternalURL


Identity                      : EX2016\mapi (Default Web Site)
Server                        : EX2016
IISAuthenticationMethods      : {Ntlm, OAuth, Kerberos, Negotiate}
InternalAuthenticationMethods : {Ntlm, OAuth, Kerberos, Negotiate}
ExternalAuthenticationMethods : {Ntlm, OAuth, Kerberos, Negotiate}
InternalUrl                   : https://ex2016.domain.local/mapi
ExternalUrl                   : https://ex2016.domain.local/mapi



 C:\Windows\system32>
PS>Get-PowerShellVirtualDirectory | fl Identity, server, *Auth*, InternalURL, ExternalURL


Identity                      : EX2016\PowerShell (Default Web Site)
Server                        : EX2016
CertificateAuthentication     : True
InternalAuthenticationMethods : {}
ExternalAuthenticationMethods : {}
LiveIdNegotiateAuthentication : False
WSSecurityAuthentication      : False
LiveIdBasicAuthentication     : False
BasicAuthentication           : False
DigestAuthentication          : False
WindowsAuthentication         : False
OAuthAuthentication           : False
AdfsAuthentication            : False
InternalUrl                   : http://ex2016.domain.local/powershell
ExternalUrl                   :



 C:\Windows\system32>
PS>Get-ExchangeCertificate | fl Identity, FriendlyName, Subject, CertificateDomains, Services, Issuer, *not*, Status


Identity           : EX2016.domain.local\xxxx_Cert_1_xxxx
FriendlyName       : Microsoft Exchange Server Auth Certificate
Subject            : CN=Microsoft Exchange Server Auth Certificate
CertificateDomains : {}
Services           : SMTP
Issuer             : CN=Microsoft Exchange Server Auth Certificate
NotAfter           : 10.09.2026 15:12:39
NotBefore          : 06.10.2021 15:12:39
Status             : Valid

Identity           : EX2016.domain.local\xxxx_Cert_2_xxxx
FriendlyName       : Microsoft Exchange
Subject            : CN=EX2016
CertificateDomains : {EX2016, EX2016.domain.local}
Services           : IIS, SMTP
Issuer             : CN=EX2016
NotAfter           : 06.10.2026 15:11:29
NotBefore          : 06.10.2021 15:11:29
Status             : Valid

Identity           : EX2016.domain.local\xxxx_Cert_3_xxxx
FriendlyName       : WMSVC-SHA2
Subject            : CN=WMSvc-SHA2-EX2016
CertificateDomains : {WMSvc-SHA2-EX2016}
Services           : None
Issuer             : CN=WMSvc-SHA2-EX2016
NotAfter           : 04.10.2031 12:32:50
NotBefore          : 06.10.2021 12:32:50
Status             : Valid

Identity           : EX2016.domain.local\xxxx_Cert_4_xxxx
FriendlyName       : real.domain.org (rapidssl rsa ca 2018)
Subject            : CN=real.domain.org
CertificateDomains : {real.domain.org}
Services           : IMAP, POP, SMTP
Issuer             : CN=RapidSSL RSA CA 2018, OU=www.digicert.com, O=DigiCert Inc, C=US
NotAfter           : 05.11.2021 13:00:00
NotBefore          : 07.10.2019 02:00:00
Status             : RevocationCheckFailure



 C:\Windows\system32>
PS>Get-OrganizationConfig | fl MapiHttpEnabled


MapiHttpEnabled : True


 C:\Windows\system32>
PS>Get-CasMailbox -Identity Dummy.User | fl MapiHttpEnabled


MapiHttpEnabled :


 C:\Windows\system32>
PS>Stop-Transcript