To Generate a CSR on Microsoft Exchange 2003 follow the instructions below:
- Click Start, point to Programs, point to Microsoft Exchange, and then click System Manager.
- If the Display administrative groups option is turned on, expand Administrative Groups, and then expand First Administrative Group (where First Administrative Group is the name of your administrative group).
Note To display administrative groups, right-click Your_Organization, click Properties, click to select the Display administrative groups check box, click OK two times, and then restart Exchange System Manager.
- Expand Servers, expand the Exchange Server container that you want to configure, and then expand the Protocols container.
- Expand each protocol that you want to configure, right-click the Default Protocol_Name virtual server object, and then click Properties.
- Click the Access tab, and then click Certificate.
- In Web Server Certificate Wizard, click Next, click Create a new certificate, and then click Next.
- Click Prepare the request now, but send it later, and then click Next.
- Either type an appropriate name for the certificate in the Name box, or leave the default setting of Default Protocol_Name Virtual Server.
- In the Bit Length list, click the bit length that you want to use, and then click Next.
- In the Organization box and the Organizational unit box, type the organization and the organizational unit information, and then click Next.
- In the Common name box, type the common name for your site, and then click Next.
Note If you want to allow access from the Internet, this name must be a fully qualified domain name (FQDN) that can be resolved externally. This FQDN must map to the IP address that is linked to the virtual server. IP addresses are not accepted.
- In the Country/Region list, click your country or your region name.
- In the State/Province box, and in the City/Locality box, type the information that is appropriate for your organization, and then click Next.
- In the File name box, do one of the following:
- Type a name and a path for the location where you want to create the certificate.
- Leave the default file name in this box.
- Click Next.
- Review the information that is on the Request File Summary page. If something is not correct, click Back until you reach the page that must be corrected, and then click Next until you return to the Request File Summary page, and then click Next.
- The final page confirms that a certificate with the specified file name has been created. The default setting is drive name:\certreq.txt.
- Click Finish.
For Instructions how to install the SSL Certificate see solution : SO14490
These instructions were extracted from Microsoft's website. Note that Microsoft has End-Of-Life Exchange 2003 as of April 8, 2014. See this article for more information.