How does SSL certificate work?

I built some certificate servers by myself for our exchange2003 webemail and rpc over http purpose. I thought I knew the answer already, but I confused again.

From my understanding, certificate is an encryption method, and also for ensuring the identity of a remote computer. But when I am trying to access an ssl site, there is a security dialog box showing up with ! sign as below:

1): The security certificate was issued by a company you have not chosen to trust. View the certificate to determine whether you want to trust the certifying authority
2): The name on the security certificate is invalid or does not match the name of the site

I'm kind of understand the first one, but what is the second one, I know how to fix it by match the dns name. but what about if I don't do that, but just click OK button to enter the site. looks like I can still access the site without any problem. so my question is what is the purpose of that.

Thank you very much,
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Naser GabajE&P Senior Software SpecialistCommented:
Greetings JerryJay,

Can this help:

Good Luck!

(2) when you create your the "common name" spot you should put the fully qualified dns name of the server (as you will be referring to it). Meaning... if if your OWA site is '" you should put that in the common name field even if you have other names for that server.  The name mismatch occurs when the hostname of the site in the browser doesnt match the common name field in the cert. They have to match exactly or else use a wildcard cert (*  

(1) You get a warning about not being from a trusted CA because you created the cert yourself. Anyone can create an ssl certificate for any site. But unless it was issued by a valid, known and trusted certificate authority most browsers will give you that message. The traffic is just as encrypted and secure, the user only has an extra step to proceed.
JerryJayAuthor Commented:
It is great, I very much appreciate for all the helps.

Naser GabajE&P Senior Software SpecialistCommented:
>>It is great, I very much appreciate for all the helps
well, what is that mean, if any answer helped you, then you should accept it, if more than one then split the points.

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