I found an error in the /opt/zimbra/log/mailbox.log on my zimbra server
2019-11-25 14:12:11,593 ERROR [ScheduledTask-2] [email@example.com;mid=116;ds=external;] gal - Error executing gal search com.zimbra.cs.ldap.LdapException: LDAP error: - unable to get connection: ldap host=: An error occurred while attempting to connect to server 10.1.1.113:389: java.io.I OException: An error occurred while attempting to establish a connection to server 10.1.1.113:389: java.net.NoRouteToHostException: No route to host (Host unreachable) ExceptionId:ScheduledTask-2:1574709131591:9a9c87a96380de5c Code:ldap.LDAP_ERROR
I also executed the following:
zmprov gd domain.com zimbraGalLdapURL # name domain.com zimbraGalLdapURL: ldap://10.1.1.113:389
At one time my zimbra ldap server had the ip address of 10.1.1.113 – but it does not any more
to fix the problem, I executed
zmprov md softwareeffect.com zimbraGalLdapURL "ldap://mail1.domain.com:389"
where: mail1.domain.com is the FQDN of the zimbra ldap server