Office 365 outlook certificate error

Is the domain hosted on Microsoft or third party hosting company?

What version of Microsoft Outlook are you using?

How did you update to the latest Office 365?

Thanks.

Screenshot of the error might be useful, most importantly what is the server name that you see there?

Screen capture is attached.
It will be Outlook 2016 as it only occurred after the user up-dated to the latest version.
I think that the domain name is hosted by a third party - salmac.co.uk is the domain

Your MX Record seems to be ok. I have not seen an attachment of error message. Kindly reattach and resend.

Thanks.

OK - I seem to have made a mistake the last time
Capture.JPG

It seems you are trying to use remote.salmac.co.uk to configure your Office 365 account. I believe this domain doesn't have an SSL therefore you are getting that error.

I would suggest using outlook.office365.com instead.

You can use the link below for reference to configure office365 instead:

https://kb.wisc.edu/office365/page.php?id=28019

I can't quite see from that link exactly what I would have to change..

Basically, you use office.outlook365.com instead of remote.salmac.co.uk.

Try configuring the account manually, whereby you have to supply the mail server name yourself.

Thanks.

The customer has gone home now so this will have to be on hold until tomorrow.
Thanks in the meantime though

OK - the problem is that the certificate is being issued by the local machine - that much has been established. I have stopped all of the Exchange services - as exchange is no longer used locally - but the problem still persists.

Is there perhaps something else which I can disable to stop this?

Did you clear the Autodiscover SCP in AD? Again, a quick fix is to use the reg keys here, they dont require any changes made on the server (or in AD): http://support.microsoft.com/kb/2212902

OK - do you simply add a key and name it - e.g. ExcludeScpLookup ?
Under Autodiscover all I have is a RedirectServers sub-folder with :-

(Default)                                            REG_SZ             (value not set)
autodiscover.hotmail.com             REG_NONE      (zero-length binary value)
autodiscover-s-outlook.com          REG_NONE      (zero length binary value)

Yup, just create a DWORD value for ExcludeScpLookup and set it to 1, then restart Outlook on the machine. And repeat for any other methods as necessary.

I have added the following values - as shown in the attachment but the problem persists.
They are directly under Autodiscover and not Autodiscover\RedirectServers
Capture.JPG

I changed the case on the SpcLookup key and that solved the problem - thanks

Well, you are practically excluding all methods now. Leave at least the HTTPredirect one (CNAME), so that you can actually connect to O365 :)