LDAP

To Change the LDAP server to the local host (will mess up upgrades though)

zmlocalconfig -e ldap_url=ldap://localhost:389
zmlocalconfig -e ldap_master_url=ldap://localhost:389
zmlocalconfig -e ldap_host=localhost

ZMTOP

Use the zmtop command to track down mailbox usage and performance issues.

zmtop

Z-Push

To avoid errors in Zimbra backend, change the following Zimbra settings

zmlocalconfig -e zimbra_waitset_max_per_account=20
zmlocalconfig -e zimbra_session_limit_admin=20

To Install Z-Push

vi /etc/apt/sources.list.d/z-push.list

And set contents to

deb http://repo.z-hub.io/z-push:/final/Ubuntu_16.04/ /

To Install

wget -qO - http://repo.z-hub.io/z-push:/final/Debian_8.0/Release.key | sudo apt-key add -
sudo apt-get update
sudo apt-get install z-push-config-apache z-push-ipc-sharedmemory
./z-push-admin.php -a fixstates

NextCloud

After upgrading NextCloud, the Zimbra plugin is installed but not enabled. The database needs to be updated.

I have managed to gain access again to the nextcloud installation enabling the zimbra plugin via database and, lately, removing it from the installation. The problem seems that it is incompatible with the version 14, but the disable does break something.

Enabling Zimbra Drive (update oc_appconfig set configvalue="yes" where appid="zimbradrive" and configkey="enabled";) fixed the issue for me as well.

https://github.com/nextcloud/server/issues/11854