Configure authentication with Active Directory - Zimbra :: Tech Center
LDAP - Active Directory Integration
Configuring SPNEGO Single Sign-On - Zimbra :: Tech Center
How to setup External Active Directory Authentication
Zimbra #04 Integration with Active Directory Server
The Complete Guide to Install Zimbra in CentOS7 - (OSE)
Installing an SSL certificate on Zimbra - Hosting
What the Vuln: Zimbra
Administration Console and CLI Certificate Tools - Zimbra - Tech
Zimbra Collaboration Administrator Guide