Outlook Mobile App not connecting to Exchange 2010 as of 26/03/21

I have managed to get this working on an environment I administer.

This is only a temp fix and the client is moving to a cloud email solution in the coming days.

The environment for me: SBS 2011. Exchange 2010 CU32

The fix I had used is this;

Within HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols - There are sub keys for SSL 2/3 and TLS 1.0/1.1/1.2

Within each, are 2 more keys labelled 'Client' and 'Server'

Each with Values for "DisabledByDefault" and "Enabled"

Check to make sure both SSL 2.0 & SSL 3.0 on each value are set to 0 (decimal)

Within the 3 TLS keys. The same values in "Client" & "Server", change the "Enabled" value to 1 (decimal)

Check the permissions on the below folder;

C:\ProgramData\Microsoft\Crypto\RSA\MachineKeys

Ensure that the following permissions are set.

Reboot the server.

The above worked for me, it could have been a specific issue, but I thought best to share.
I have since reverted the changes, not due to any issue, but to not confuse things for my users following reverting to the native mail apps.
I am reserving the Outlook app for Friday when they go live on the new email system to avoid confusion.

I also had run that update, but way before this happened. We only saw the issue ourselves after the Outlook update.

We installed KB5000978 on 05/03/21, ran a full 3 weeks before the Outlook mobile app updated.

Once since that mobile update (for us at least), did the issue occur on both platforms.

Just wouldn't want you to look at your Exchange Server update causing this and rolling it back :)

.

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But I totally agree this needs to be escalated and really cannot afford the response to be "Exchange 2010 is end of life, upgrade to Exchange 2019 or Microsoft 365".

Unfortunately money is a constraint for customers at this time, and an upgrade to an email system which works, wont be a high priority, I'm sure others can relate.

Just a heads up, which I have explained in the private message to you also. But for public reference.

I have 2 completely separate customers with Exchange 2010 (Installed from SBS 2011). Both have been working for years with no adjustments (Apart from the rollups as needed).

Microsoft Outlook for Mobile (Both Android and iOS) had an update last week, then all of a sudden, Outlook stops working on Exchange 2010.

OWA is working fine.

Active Sync on EVERY other mail app I can think of, works fine connecting to Exchange. (Which is our current workaround).

I think you may be looking at the wrong thing here George, as the only change is the update to Outlook (for Mobile).

Also - lots of other people on other forums and here have reported the same issues....

Seems a little unlikely that everyone decided to break their Exchange 2010 servers at the same time don't you think?

Is there an ETA on this, by all accounts this has been broken for over 2 weeks now?

If I was looking at this cynically then it looks like a method for Microsoft to force people into updating.

Hi GEEVES92,

Many thanks for the information you given. So, this issue could be contributed by your Active Sync for your exchange2010 server. So to check if the ActiveSync is working properly, you can follow our suggestion here. So exchange ActiveSync is a feature of exchange server 2010 that is installed by default when you install the Client Access server role. 

Here are a few things as ad admin you may have a look on it:

• Exchange ActiveSync mailbox policies.
• DNS A record - It isn't mandatory. Makes it easier to type when you are setting up the phones
• Firewall NAT - Create NAT rules to allow 80 and 443 to go to your Exchange server from outside your company.
• Public Certificate - Most phones require that you have a public certification.
• Activesync tab configured - Inside the Server -> Client Access section of Exchange there is an Activesync tab.  Make sure that the external link shows your public DNS name and not the internal one.

And for configuring account not working part, you should look especially at the OutlookAnywhere and AutoDiscover settings are setup properly

Once the above is configured properly and check it again see if your users could configure their account on their mobile device.

Yours Sincerely,

George