Integrate Nextcloud, ownCloud or any WebDAV server to your Zimbra webmail
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Zimbra WebDAV Client

If you find Zimbra WebDAV Client useful and want to support its continued development, you can make donations via:

Demo video:

User manual :

Integrate any WebDAV server in Zimbra Collaboration, currently tested with ownCloud 9.1, Nextcloud 14-15, Alfresco Enterprise - 5.2.0 and Nuxeo.

Supported Zimbra versions 8.8.11.

Zimbra Desktop is not supported and does not work. Ubuntu 12.04 is not supported ( If you have trouble installing on Ubuntu see below on the known issues.

Bugs and feedback:

Report security issues to (PGP fingerprint: 97f4694a1d9aedad012533db725ddd156d36a2d0)

Nextcloud Tab in Zimbra Preferences Dialog Attach from Nextcloud


Install prerequisites

  • A running Zimbra server
  • A running WebDAV server (for example ownCloud/Nextcloud)

Downloading the automated installer

wget --no-cache -O /tmp/
chmod +rx /tmp/

Multi server support

The zimlet and extensions support multi server ZCS cluster setups where proxies and mailboxes are in different machines. The zimlet and extensions should only be installed on the mailbox servers. The zimlet and extensions must be installed on all of your mailbox servers (refer to the Installing section).


Use the automated installer (Interactive mode):

[zimbra@server zimbra]$ zmmailboxdctl restart

Use the automated installer (Non interactive mode):

/tmp/ --auto
[zimbra@server zimbra]$ zmmailboxdctl restart

Non interactive mode does not enable experimental Libreoffice document preview, automatically installs the Zimlet (in production mode) and force enables it in all COS'es. It also installs public link sharing.

Online document editing (OnlyOffice)

Using Zimbra WebDAV Client you can preview and edit docx,xlsx,pptx,txt and md directly from the Zimbra UI using the power of OnlyOffice by configuring your OnlyOffice Document Server API url in owncloud_zimlet_onlyoffice_api_url. See owncloud_zimlet_enable_onlyoffice below.

In order to make sure OnlyOffice integration works, specially in muti server ZCS clusters, make sure that all of your domains have defined:

  • zimbraPublicServiceHostname
  • zimbraPublicServiceProtocol
  • zimbraPublicServicePort

values which can be found at:

  • Configure
  • Domains
  • General Information
    • Public service hostname:
    • Public service protocol: https
    • Public service port: 443

Document preview

Zimbra WebDAV Client uses OnlyOffice, LibreOffice and jsPDF to display previews of your documents. To enable LibreOffice preview, re-run the installer and choose Y when asked to install LibreOffice Document Preview. Previews are supported for the following file types: pdf,jpg,jpeg,png,txt,md (markdown rendering). Video playback results may be poor supported types: mp4 and webm. If you enabled the optional LibreOffice conversion in the installer, these file types are previewed as well: docx,doc,xlsx,xls,pptx,ppt,odt,ods,odp. On CentOS 7 only (see extras folder): djvu. On top of that the Zimbra WebDAV Client supports editing and redering plain/text and markdown documents. If you install both OnlyOffice and LibreOffice, docx,xlsx and pptx will be renderered using OnlyOffice and odt,ods and odp using LibreOffice.

Configure bruteforce protection

Zimbra WebDAV Client sends all requests to Nextcloud with an X-Forwarded-For HTTP header. You must configure Zimbra and Nextcloud properly to avoid problems with Nextcloud's bruteforce protection mechanism.

On Zimbra:

#Check current config
zmlocalconfig zimbra_http_originating_ip_header
zimbra_http_originating_ip_header = X-Forwarded-For
zmprov gcf zimbraMailTrustedIP #default empty

#Add Zimbra Proxies and Zimbra Server
zmprov mcf +zimbraMailTrustedIP <zimbra server proxy ip here>

#This needs to be told to Zimbra WebDAV Client as well (workaround for an issue in upload handler)
echo -n "zimbramailtrustedips=" >> /opt/zimbra/lib/ext/ownCloud/
echo $(su zimbra -c "/opt/zimbra/bin/zmprov gcf zimbraMailTrustedIP | cut -c22- | tr '\n' ';'") >> /opt/zimbra/lib/ext/ownCloud/

Then in Nextcloud config.php:

'trusted_proxies' => array('<zimbra server proxy ip here>'),
'forwarded_for_headers' => array('HTTP_X_FORWARDED_FOR'),

You do not need to restart anything after changing these IP.

Configuring preferences

Each user can configure the WebDAV Client for themselves by clicking Preferences in the Zimlet menu.

Initially the Preferences dialog will be filled with best guess values and values provided by the administrator in

It is recommended that the administrator reviews the and change it to fit the needs. Doing this simplifies things for your users. You can find the configuration in /opt/zimbra/lib/ext/ownCloud/

Please note that a preference set by the user has priority over a preference set in And has priority over best guess preferences.

property name default value description guessed value
allowdomains * A semicolon separated DAV server allow list. Default * allows all. Example: *;
disable_password_storing false When true, users can not store their passwords in plain text in LDAP
owncloud_zimlet_server_name URL to your WebDAV/ownCloud server. Example: location.protocol + '//' + location.hostname
owncloud_zimlet_server_port Port number for your WebDAV/ownCloud server. Example: 443 ((location.protocol === 'https:') ? 443 : 80)
owncloud_zimlet_server_path /nextcloud/remote.php/webdav/ Part of the URL where server handles WebDAV protocol without protocol and hostname.
owncloud_zimlet_oc_folder /nextcloud Location where ownCloud/nextCloud is installed without protocol and hostname.
owncloud_zimlet_disable_rename_delete_new_folder false When true, rename folder, new folder and delete folder operations are hidden from the UI. To avoid bugs in ownCloud 8 with external storage.
owncloud_zimlet_extra_toolbar_button_title Go to Nextcloud If a value is set, show an additional button in the WebDAV tab to open in a new browser window the url set in owncloud_zimlet_extra_toolbar_button_url.
owncloud_zimlet_extra_toolbar_button_url owncloud_zimlet_oc_folder URL to open when Go to Nextcloud is clicked. Instead of a URL you can set it to owncloud_zimlet_server_name it opens the URL set in owncloud_zimlet_server_name (may be set by user). When set to owncloud_zimlet_oc_folder it opens the URL set in owncloud_zimlet_server_name combined with owncloud_zimlet_oc_folder (maybe set by user). See: owncloud_zimlet_extra_toolbar_button_title
owncloud_zimlet_app_title WebDAV Change this if you want to rebrand WebDAV Client for your users. For example: ownCloud.
owncloud_zimlet_max_upload_size 104857600 (100MB) Maximum upload size for upload dialog MB * 1024 * 1024. The back-end has a hardcoded maximum of 1048576000 (1GB).
owncloud_zimlet_use_numbers false If set to true, a number will be used instead of filename when saving attachments.
file_number 1000000 The number to start counting from. See owncloud_zimlet_use_numbers.
owncloud_zimlet_disable_ocs_public_link_shares false Controls if users can share items with a public link. Set this to true if you use a DAV server that is not ownCloud/Nextcloud or if you want to disable public link sharing.
owncloud_zimlet_welcome_url Page to load in the preview window when then the tab is clicked.
owncloud_zimlet_accountname_with_domain false When false the username field in settings dialog is set to username, when true it is set to
owncloud_zimlet_disable_auto_upload_on_exceed false When true, the user will not be asked to use WebDAV if attachment size exceeds Zimbra limit. This feature is for compatibility with other Zimlets (RMail)
owncloud_zimlet_enable_onlyoffice false When true, enable right-click menu action and edit in Nextcloud/ownCloud OnlyOffice app.
owncloud_zimlet_onlyoffice_api_url Set to Document Server API URL to enable OnlyOffice preview of docx,xlsx,pptx:
owncloud_zimlet_onlyoffice_secret If configured, a token is send to Only Office Document server allowing you to restrict access to DS to only trusted users. (WebDAV Client currently does not sign parameters)

After changing run the following:

wget -O /tmp/
wget -O /tmp/prop2xml.jar
chmod +rx /tmp/
source /tmp/

(Development mode):

java -jar /tmp/prop2xml.jar tk_barrydegraaff_owncloud_zimlet /opt/zimbra/lib/ext/ownCloud/ /opt/zimbra/zimlets-deployed/_dev/tk_barrydegraaff_owncloud_zimlet/config_template.xml

(Production mode):

java -jar /tmp/prop2xml.jar tk_barrydegraaff_owncloud_zimlet /opt/zimbra/lib/ext/ownCloud/ /opt/zimbra/zimlets-deployed/tk_barrydegraaff_owncloud_zimlet/config_template.xml
zmzimletctl configure /opt/zimbra/zimlets-deployed/tk_barrydegraaff_owncloud_zimlet/config_template.xml
zmcontrol restart

Restrict allowed DAV Servers

Your clients can connect to all dav servers by default, you can restrict the allowed DAV servers to connect to in:


No service restart is needed after changing this file.

Storing your password in the Zimlet?

When the user stores the Nexctloud password on the Zimlet, that password is stored unencrypted in the Zimbra LDAP. As an admin you can either disable the storing of the password OR let your users use an app password or device password see

Use the Nextcloud logo and name in the Zimbra UI

If you use WebDAV Client to connect to Nextcloud (most of us do) you can do a trick to use the Nextcloud logo and name in the Zimbra UI. From your Zimbra server as root:

git clone
cd owncloud-zimlet

Un-installing (For both production and development mode)

rm -Rf /opt/zimbra/zimlets-deployed/_dev/tk_barrydegraaff_owncloud_zimlet/
rm -Rf /opt/zimbra/zimlets-deployed/_dev/tk_barrydegraaff_docconvert/
rm -Rf /opt/zimbra/lib/ext/ownCloud/
rm -Rf /opt/zimbra/lib/ext/OCS
rm -Rf /opt/zimbra/lib/ext/DocConvert/
zmzimletctl undeploy tk_barrydegraaff_owncloud_zimlet
# It's ok if zmzimlet uninstall fails in development mode
[zimbra@server zimbra]$ zmmailboxdctl restart


The Zimbra WebDAV Client uses built-in language strings from Zimbra, as such it is translated for all languages that are supported by Zimbra.

Known issues and troubleshooting:

  1. Installer does not work on Ubuntu fails to get the sources from git. This is a suspected cache issue, try again after 10 minutes, if that does not work open the and change OWNCLOUD_ZIMLET_CLONE_URL to or or git://
  2. Passwords with characters like @ will not work, try to install this using a simple account and password (A-Za-z0-9). fixed in 0.6.2.
  3. Error 500 but some features work, if you use ownCloud external storage, make sure it is available and marked green.
  4. Running a WebDAV server behind and NGINX reverse proxy (from CentOS or Debian) won't work, it will work when proper options are enabled (as for example with zimbra-proxy, also based on NGINX).
  5. Delay of 30 seconds in response from Nextcloud, the brute force login protection has kicked in. Configure X-Forwarded-For see above! Or and this is not recommended: set in your Nextcloud the preference '' => false, and issue truncate table bruteforce_attempts;





Copyright (C) 2015-2019 Barry de Graaff A Zeta Alliance Zimlet, Michele Olivo ZeXtras

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see