Usually it happens when the SSL is installed using Exchange Management Shell. There is no ability to specify the certificate to use. To choose the SSL, you have to use the IIS Manager.
IIS 6
- Right click on the site which contains OWA folder.
- Click Properties.
- Click Directory Security tab.
- Under Secure communications section click Server Certificate.
- Enter Web Server Certificate Wizard
- Click Next.
- Click Replace.
- Now select the new SSL product from the list and click Next.
- Check the details and click Next.
- Click Finish to exit the wizard.
IIS 7
- Find the site which houses OWA folder. The center of window should display the name of website.
- Select Bindings under the Edit Site menu.
- Web Site Bindings
- Click https option and click the Edit button on the right.
- In SSL section choose from drop-down menu the new certificate.
- Click OK to complete the Installation. Double click on OWA to see if it is correct.
