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Outlook 2013 have certificate warning with sbs2011 (Exchange 2010). Selfsigned cert is used. Only domain-members have the problem

Hi,

we have a sbs2011 with Exchange 2010. As domain we have via wizard in the console used remote.realdomainname.com . If i ping remote.realdomainname.com it ping sthe ip of the local server. In DNS there is the right Entry i think. On top we entered the line "192.168.10.2 remote.realdomainname.com" in the hosts file.
We have some workstations which are members of the network-domain and some workstations are only in a workgroup.
Only the workstations which are domainmembers, throw a warning at the start of Outlook. Outlooks says that the certificate realdomainname.com is not valid.
Outlook tries to go out on the webserver a looks at this ssl-certificate instead of looking directly over lan to the exchange-server.
I tried to use proxy-settings in outlook without any success.

Any ideas ?

loosain
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loosain
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loosain
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2 Solutions
 
MIRSYSCommented:
Well it's probably because you didn't create an A record for "autodiscover.yourrealdomain.com" in the internal DNS.
Also don't use hostfile entries. If your DNS is functioning well you wouldn't need it.
However I'm not clear on how you wouldn't get a certificate warning on all clients given you're not using a trusted cert.
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loosainAuthor Commented:
The cert on the server is trusted. But the non-domain-members talk directly with the server and trust his cert. The domain-members go via internet and use the ssl-cert of the webserver. I don´t know the reason. Therefor i added the hosts entries for testing. ITs much faster and easier than testing by configuring dns-server...
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MIRSYSCommented:
like I said it's probably because they are doing a lookup to autodiscover.
What does the certificate warning say exactly?
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loosainAuthor Commented:
It says that the certificate is not valid because of wrong domainname and validation time is over.
That´s because it is the ssl-certificate of the webserver not of the local exchange server. There is no ssl in use on webserver so there is an old provider-cert there.
I dont get the point why those computers which are domain-members look at the internet and the non-domain-members look directly to the exchange server.
If it would be a dns problem, it should have been fixed by adding remote.domain.com and autodiscover.domain.com to the hosts file.
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MIRSYSCommented:
what happens when you manually configure outlook and enter the hostname of the server?
Or are you trying to use outlook anywhere?
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loosainAuthor Commented:
Just tested - same warning by manually configuring it.
Normaly outlook finds out by itself name, server etc if the computer is domain-member. Now i just tried to enter those data manually. It worked and outlook connected but there was again this certification warning belonging to the certificate of the internet-webserver.
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loosainAuthor Commented:
It must have been something with active directory, because only domain-members are trying to connect over internet. The other computers cant connect to AD and then they just talk via lan to the exchange server (as i want them to)
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loosainAuthor Commented:
Found out something new:
If i start "Email Autoconfiguration" in Outlook it always shows the wrong url for inernal and external Url:
yourrealdomain.com instead of remote.yourrealdomain.com

So i (just for testing) add server-ip with yourrealdomain.com in hosts...
No warning, no error ! But now i cant surf to the website yourrealdomain.com, because it is placed on the webserver and not on the Exchange-server...
What can i do to change the information about internal urls provided to the clients via autoconfiguration ?
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loosainAuthor Commented:
The clue was to make a working SSL-cert for the webserver. In DNS we let show autodiscover.domain.tld to the wrong IP. Then Outlook tries remote.domain.tld .This is hosted by the Exchange-Server and therefor there is the right cert there. Now everything works
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