Certificate Error when Outlook Client Connects (and web mail)

[dsearles]

Hi guys,

 

Got some funny stuff happening with exchange/outlook/certificates... was wondeirng if anyone is seeing the same issues?

 

Following the windows updates sent out on Tuesday evening (11th March 2014) I am having trouble when users open the Outlook Client....

 

 

When my users launch Outlook they are prompted with the following pop up error:

 

 

 

 

Information you exchange with this site cannot be viewed or changed by others. However, there is a problem with the sites security certificate.

 

An Unknown error occurred

 

This site should not be trusted.

 

 

 

 

 

 

When they click through the error, Outlook works fine.

 

 

Users are also having trouble accessing the web mail portal (similar certificate error).

 

 

This is on random PC's with random users?

 

 

I have a feeling it's related to the recently revoked Entrust.net Secure Server Certification Authority from Internet Explorer? But I'm at a bit of a loss??

 

 

Any advice would be appreciated?

 

 

Thanks

 

 

David

[dsearles]

Hi,

 

Just in case anyone is having the same issues. In the end it was certificate errors stemming from Comodo and a revoked Entrust certificate:

https://support.comodo.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=1427

 

Once I rolled out the new certificate via GPO, the problem has disappeared...

 

Not great from Comodo mind, they could of let people know in advance... would of saved me a couple of days of hair pulling!