Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

there is problem with the proxy server security certificate. the name on the security certificate is invalid or does not match the name of the target site

i got this error message when I try to open my outlook account, my outlook email is connect with exchange server but this message appear before it connect, I don't know where is the problem, somebody help me.


share|improve this question
It's a little hard to help with this level of detail. What's the name on the CAS that you're connecting to? How's the client configured? What's the name on the certificate that you were sent instead? What's the proxy doing, and how is it configured? – Shane Madden Dec 18 '11 at 7:50

The error message you've quoted pretty much tells you exactly what the problem is.

The SSL certificate on your OWA server does not match the hostname of the server. One example of why this might occur is if you use a different DNS namespace internally and externally. e.g. exchange.example.local internally and externally and you are attempting to connect from an external location, when the certificate was designed for internal only use. If you don't use a certificate that includes the other (external in my example) hostname as a Subject Alternate Name (SAN), then you will have this problem.

Unfortunately, as @Shane has pointed out, you don't give enough info for anyone to give any specific help to you, however if you could edit your question and give a little more info, I'm sure you'll get a more specific answer than is currently possible.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.