Failing Office 365 Migration

[AceDaz]

Hi

 

I recently migrated our emails from Exchange 2010 on-premises to Office 365 using a hybrid solution by installing an additional Exchange 2013 Server. I then decomissioned the old 2010 Mailbox / Internal CAS and the 2010 External CAS.

 

Staff use the Desktop version of Outlook 2010 and the Pupils use the OWA.

 

I have left the 2013 Exchange server as we have Printers and Servers which require sending out emails, but I have removed the AutoDiscoverUri from the Exchange 2013 Server by running:

Set-ClientAccessServer -Identity "EXCHANGE 2013 SERVER NAME" AutoDiscoverServiceInternalUri $NULL

 

 

The DNS Autodiscover was changed to the Office 365 CNAME entry of autodiscover.outlook.com and the SRV and DNS references to the old Exchange was removed.

 

I have also applied the following registry entries for the staff:

ExcludeHttpsRootDomain DWORD:1

ExcludeLastKnownGoodURL DWORD:1

ExcludeSCPLookup DWORD:1

ExcludeSRVRecord DWORD:1

In the following keys:

HKCU\Software\Microsoft\Office\14.0\Outlook\AutoDiscover

HKCU\Software\Policies\Microsoft\Office\14.0\Outlook\AutoDiscover

 

 

I have also removed the following Exchange AD Attributes in user AD Accounts:

"HomeMDB", $null

"HomeMTA", $null

"msExchMailboxAuditEnable", $null

"msExchAddressBookFlags", $null

"msExchArchiveQuota", $null

"msExchArchiveWarnQuota", $null

"msExchBypassAudit", $null

"msExchDumpsterQuota", $null

"msExchDumpsterWarningQuota", $null)

"msExchHomeServerName", $null

"msExchMailboxAuditEnable", $null

"msExchMailboxAuditLogAgeLimit", $null

"msExchMailboxGuid", $null

"msExchMDBRulesQuota", $null

"msExchModerationFlags", $null

"msExchPoliciesIncluded", $null

"msExchProvisioningFlags", $null

"msExchRBACPolicyLink", $null

"msExchRecipientDisplayType", $null

"msExchRecipientTypeDetails", $null

"msExchTransportRecipientSettingsFlags", $null

"msExchUMDtmfMap", $null

"msExchUMEnabledFlags2", $null

"msExchUserAccountControl", $null

"msExchVersion", $null

 

All the mailboxes are migrated over and I have removed the hybrid.

 

But I am having issues with Outlook 2010 connecting to Office 365.

 

1. Outlook can sit there for ages showing:

 

 

2. Outlook can report that on the bottom right that it is Connecting...but never connects.

 

3. Outlook reports that it is Offline

 

4. When adding a new profile into Outlook, it can fail:

 

5. Outlook says connecting or offline for a long time and then randomly connect.

 

 

I have run an Outlook Test E-Mail Auto Configuration test from different machines, and it shows this:

 

What confuses me, is that it has picked up a SRV Record from somewhere for our domain. But we use split DNS and internally there are no SRV records apart from the usual:

_ldap

_kerberos

_kpasswd

_gc

_VLMCS

 

The only other place I can think of is with AD itself, but...

 

I have removed 3 entries in the

Configuration > CN=Configuration > CN=Services > CN=Microsoft Exchange > CN=OUR EXCHANGE NAME > CN=Client Access > CN=AutoDiscover > CN=Outlook

 

I have removed entries within the following relating to URLs or Autodiscover:

Configuration > CN=Configuration > CN=Services > CN=Microsoft Exchange > CN=OUR EXCHANGE NAME > CN=Administrative Groups > CN=Exchange Administrative Group (FY*************) > CN=Servers > CN=NEW 2013 EXCHANGE SERVER FOR HYBRID

 

 

Has anyone else come accross this when migrating to Office 365?

 

Any ideas? As this is driving our staff around the bend (including me!!)