Zimbra 8.x Comodo Signed SSL installation


This tutorial is for how install Comodo Signed certificate for Zimbra 8.x when the installation via webadmin gui is not working or giving you errors. It should work but i find it quite often fails despite having the proper keys and certs no matter what. Makes it a real pain to debug if your not a Sys Admin.

If you have not already we recommend generating the CSR via GUI admin area before continuing. See the below Zimbra documentation for reference.

You should have the CSR generated before continuing.

login to zimbra server via ssh

Then change to zimbra user

su - zimbra

Then cd to zimbra ssl directory

cd /opt/zimbra/ssl/zimbra/commercial/

create a file called commercial_ca.crt

nano commercial_ca.crt

Paste in the contents of the 3 ca certs in that file in the below order
Root CA Certificate – AddTrustExternalCARoot.crt
Intermediate CA Certificate – COMODORSAAddTrustCA.crt
Intermediate CA Certificate – COMODORSADomainValidationSecureServerCA.crt

Should look similiar to the below for Comodo

[encoded data for Root CA Certificate – AddTrustExternalCARoot.crt]


[encoded data for Intermediate CA Certificate – COMODORSAAddTrustCA.crt]


[encoded data for Intermediate CA Certificate – COMODORSADomainValidationSecureServerCA.crt]


Create a file called commercial.crt

nano commercial.crt

Paste in the contents of the signed ca.crt from Comodo for the domain from the zip file
Should look similiar to the below

[encoded data]



Then use the below command to verify and install the certificate

/opt/zimbra/bin/zmcertmgr deploycrt comm commercial.crt commercial_ca.crt


Then restart zimbra processes so new SSL is active

zmcontrol restart

Then go check in browser see the SSL is live.


Credits to both Comodo and Zimbra for guides

I found both missing some things and overcomplicating others but they are definitely good reference materials.

If your looking for assistance for purchasing Zimbra hosting or Zimbra assistance definitely hit us up.