Outlook cannot connect to the Office 365 email account with autoi discover

My wild guess is that the DNS manager of your DC still points to autodiscover A records of the old SBS server.

You need to:-

1. Open the DNS manager on one of your Domain Controllers.
2. Expand out the management tree until you can see your Internal Domain’s Forward Lookup Zone. Click on it, and make sure there are no A records for autodiscover.domain.local in the zone.
3. Once no autodiscover A records exist, right click the Zone name and select Other New Records.
4. Select Service Location (SRV) from the list.
5. Enter the setting for the SRV to the one of your Office 365 Exchange.
6. Hit OK to finish adding the record.
Once the SRV record is added to the internal DNS zone, Outlook and other autodiscover clients that attempt to configure themselves with a domain.local SMTP address will work properly without the Certificate errors on all versions of Exchange.

Source: https://acbrownit.wordpress.com/2012/12/20/internal-dns-and-exchange-autodiscover/

thanks for the explanation, Jackie  ~

You can easily work around this by deploying the reg keys in this article: http://support.microsoft.com/kb/2212902

All you need working for O365 is the HTTP redirect method, you can block all others.

Vasil, I looked at that link for 2013 running under Windows 10 but the registry keys are different -- I found autodiscover-s.outlook.com with a value of 0000 but the article is not clear what to do ... thanks

The reg keys are the same, only the version number will differ (15.0 for Office 2013). But they are not present by default, so you need to create them (ExcludeHttpsAutoDiscoverDomain, ExcludeHttpsRootDomain and ExcludeScpLookup should be enough).

thanks, Vasil