To install a certificate in Lotus Domino 6.5 follow the instructions below:
1) Download the Thawte Intemediate CA certificate from the following solution: INFO1384
2) Download the Server Certificate that was requested:
SSLCert.txt - which can be downloaded from: SO13187
3) To install the certificate view the instructions in the Lotus Notes FAQ:
The instructions are provided in the Lotus Domino 6.5 server documentation on the IBM website.