I successsfully installed a Go Daddy certificate on zcs-NETWORK-5.0.1_GA_1902.RHEL5_64.20080109190819 (upgrading from a self signed certificate).
This is basically how I did it:
Once installed under Certificates it shows:
1. Click Install Certificate under Certificates in the Zimbra admin panel
2. Select Generate the CSR (certificate signing request) for the commercial certificate authorizer
3. Enter information and download CSR.
4. Open downloaded CSR and paste contents into Go Daddy form
5. Once you complete domain verification, Go Daddy will email a download link for the certificate bundle zip
6. Download the Go Daddy certificate bundle using the link in the email and the ValiCert Root Certificate (valicert_class2_root.crt) from https://certificates.starfieldtech.com/Repository.go
7. Go back to Certificates in the Zimbra Administration interface
8. Click Install Certificate
9. Select Install the commercially signed certificate
1. Certificate: your.domain.com.crt
2. Root CA: valicert_class2_root.crt
3. Intermediate CA: gd_bundle.crt
10. Click Install and hope it works!
11. Restart Zimbra
No, I didn't ask for www.mail.mydomain.com either... I don't know if it's like that for all certificate providers but maybe it's normal for all Go Daddy provided certificates?
Subject Alternative Name: mail.mydomain.com, www.mail.mydomain.com