If you use a web hosting package from Strato and also operate your own Exchange server, you should pay attention to Autodiscover. By default, autodiscover is activated at Strato, but as an SRV entry and reference to Strato:
The activated setting at Strato then refers to the address autoconfigure.strato.de:
However, if you run your own Exchange server and use Strato as a smart host, you will have a problem here. In this case, Autodiscover points to the Strato servers. Unfortunately, the existing SRV record is not displayed directly in the domain administration, as can be seen in the screenshot above:
In the Strato Help there is also an article about this. It recommends switching it off on the Strato side. This is also completely correct, as the corresponding entry should point to your own Exchange server in this case.
There are 2 options for Exchange Autodiscover to work correctly:
Autodiscover via subdomain
The easiest way is to create a subdomain for Autodiscover:
In this case, the name autodiscover.domain.de must also be present on the certificate so that no certificate errors occur in Outlook. If you are running a small Exchange Server test environment or do not have a fixed IP, you can even keep this entry up to date using Strato DynDNS.
Autodiscover via SRV entry
Another option is the SRV entry, the corresponding SRV entry can also be created in the Strato domain administration:
In my case, the SRV record would look like this:
Advantage of the SRV record: No autodiscover.domain.de entry is required on the certificate. In simple terms, a single name on the certificate is sufficient for the small Exchange server if configured accordingly. A SAN certificate is therefore not absolutely necessary. However, in this case a message appears in Outlook:
However, the notice is not as annoying as permanent certificate warnings.
Incidentally, it is sufficient to use one of the two methods. I still find it easier to create a corresponding subdomain with the name autodiscover.domain.de. Corresponding SAN certificates are also available free of charge: