Zextras Team

What is Zextras Team

Zextras Team integrates a fully fledged corporate instant messaging platform inside the Zimbra WebClient, including Group and Corporate Messaging, File Sharing, Screen Sharing and informal Video Chat capabilities.

Zextras Team is not compatible with Zimbra version 8.8.11 and lower.

Frontend Features

Zextras Team includes the following front-end features:

  • Message delivery and read awareness

  • 1-to-1 Instant Messaging

  • Group Messaging

  • Corporate Messaging (Spaces and Channels)

  • Group Video Calls

  • Channel Video calls

  • File Sharing

  • Screen Sharing

  • Emojis

Backend Features

Zextras Team includes the following backend features:

  • COS and User availability

  • Built-in TURN server compatibility

  • No core installation needed. Zimlet installation through a package manager.

  • No configuration needed

  • Peer-to-Peer WebRTC protocol to avoid server load

  • Dedicated audit log


Zextras Team is licensed on a per-user basis.

Global Admins can enable its Advanced features for any number of users up to the limit allowed by the license, and only "advanced" users count towards any licensing limit.

The total number of users who have the Advanced features active can be seen in the output of the zxsuite core getLicenseInfo command under teamChatActiveCount:

zimbra@129efa51bd95:~$ zxsuite core getLicenseInfo

dateStart                                           2019-06-11 00:00:00 UTC
dateEnd                                             2019-12-31 17:00:00 UTC
expired                                             false
teamchatActiveCount                                 999

This count is updated every 15 minutes.

Zextras Chat and Zextras Team

Zimbra Chat and Zextras Team are neither compatible nor interoperable, meaning that the two products cannot coexist on any Zimbra NE infrastructure. The Zimbra Chat zimlet gets uninstalled during the installation process of the Zextras Team Zimlet package. However, Zextras Team includes all basic IM features provided by Zimbra Chat, which automatically gets enabled for all users who don’t have access to the advanced Zextras Team features. Advanced users can use all of the product’s features with other advanced users and can use 1-to-1 Instant Messaging with basic users, while Basic users can use the basic 1-to-1 features with all other users.

All users start as «Basic» users, and the «Advanced» features can be enabled by Global and Delegated admins.

Zextras Team Zimlet installation

The `com_zextras_Team Zimlet can be deployed from the "Core" section of the Zextras Adminictration Zimlet.

No configuration on the mailboxd side is needed after the Zimlet has been deployed and enabled.

URLs and Ports

To build URLs and links (e.g. for External Shares) Zextras Drive uses the default Zimbra settings for the domain of the account in use - the zimbraPublicServiceHostname property is used for the URL itself while the zimbraPublicServicePort property is used for the port.

Should any of the two not be set up, the system will always fall back to the zimbraServiceHostname and zimbraMailPort or zimbraMailSSLPort server-level properties.

For Video Chats and Instant Meetings, the following rules apply:

  • Team will work through firewalls and NATs as long as the peers can communicate each with the other - either directly or through a TURN server (which together with proper network rules is usually the solution to any WebRTC connection problem).

  • When no TURN server is set up, a default STUN server is used so clients should be able to send outbound traffic to ports 19305/19307. The actual P2P connection is established between the clients on a random unreserved port between 1 and 65535 based on the client configuration and network.

  • The default handshake/negotiation port used by most TURN servers is 3478 (incoming, UDP), but a different port can be used as long as it is properly set up> on the Team side the port is specified when adding the TURN server and the clients clients will be instructed to connect through it. The default P2P connection range when using a TURN server is 49152-65535 (usually configurable on the TURN side) so clients should be able to send data to that port range to the TURN server.

    • Most TURN servers can also be configured to use TCP insted of UDP.

Zextras Team administration

Zextras Team features can be enabled and disabled from the "Team" section of Accounts and Classes of Service in the Zimbra Administration Console.

The same options are also available via the zxsuite config command line utility:

  • Enable Zextras Team «Advanced» features

    • Property: teamChatEnabled

    • Available in: COS, account

  • Enable or disable the chat history

    • Property: historyEnabled

    • Available in: global, server, COS, account

  • Enable or disable Video Chat

    • Property: videoChatEnabled

    • Available in: global, server, COS, account

Browser compatibility

Zextras Team features are available on all browsers officially supported by the {product-short} {web-client}, with some client-side limitations:

Browser Version OS Supported

Microsoft Edge (Chromium)




Microsoft Edge (Chromium)




Microsoft Edge (EdgeHTML)




Internet Explorer




Mozilla Firefox




Mozilla Firefox




Mozilla Firefox




Google Chrome




Google Chrome












While likely to work, items marked as " Limited" are only supported on the browser’s two previous stable releases to the current one.

Google Chrome users must install the "Zextras Companion" extension to use the Screen Sharing feature, publicly available in the Chrome Web Store.

Firefox users must be sure to be running at least version 66 of the browser to be able to use the Screen Sharing feature.

Mobile App

A dedicated Zextras Team mobile app is available for both Android and iOS.

google play badge app store badge

In order for mobile message delivery to work, the Zimbra server must be able to communicate with the notifications.zextras.com service on port 443

Notifications on Android Devices

Several Android devices manufacturers have strict default settings on which apps can display notifications, sometimes causing the Zextras Team App not to be able to notify new messages.

To make sure that your device allows all required notifications, follow these steps:

  1. Log out from the app;

  2. Access the device’s Settings, then enter the "Apps & Notifications"1 menu;

  3. Select the Team app from the list of all installed apps;

  4. Enter the "Notifications"1 section;

  5. Enable the notifications (first option on the top);

  6. Enable the banner notification on the "Chat", "Group" and "Spaces & Channels" subsections;

  7. Log back in, notifications should now work;

Entries marked as (1) might have a different name depending on your device’s manufacturer and UI.


The Zextras Team UI is developed in PREACT and seamlessly integrated with the Zimbra Web Client.

The Team Tab is the full-sized Zextras Team UI, which contains all corporate instant messaging features such as Spaces and Channels. The tab itself is available for both Basic and Advanced users, but corporate features are only available to Advanced users.

Team Tab

The Team Tab is a fully fledged Zimbra feature tab that can be interacted with in the same way as all other feature tabs (e.g., Mail or Calendar).


Instant Messaging and Corporate Communication

1-to-1 chat

One-to-one Chats can start from the Team tab:

  • click on "New," then "New Chat" and select the person you want to chat with from the GAL



Groups are how users communicate with multiple people at the same time (by default up to 5 total). Those are non-persistent entities not tied to any specific space. Any user can create a group inviting people, and any group member can invite more people in the same way. When all users leave a group, the group itself ceases to exist.

Groups Features

  • A user in a Group can add more users to the Group itself up to the allowed limit.

  • A user in a Group can chat with all of the others. All members of that Group can view all messages sent to the Group.

  • A user in a Group can send files to all of the others. Files sent in a Group are available to all members of that Group.

  • An user in a Group can start a video chat with all of the others. Group video chats can be joined at any time by all members of the Group.

Global Administrators can change the allowed maximum number of group members in the Zextras Team section of the Global settings in the Admin Console.

Groups UI

Recent Group chats appear in the "Conversations" section of the Team tab.

  • Creating a Group

    To create a new Group, click on the "New" button in the Team Tab, and select "New Group."


    then, add the Group’s title, select the buddies you wish to invite and click on "Create."


  • Inviting a participant to a Group

    To invite one or more buddies to a Group expand the Group’s Info, select the users to be added and click on "Save."


  • Starting a Group Video Chat

    To start a Group video chat, click on the "Camera" icon on the top of the Group’s chat window.


    Any member of the Group can join the call at any time by clicking on the same button.

  • Leaving a Group

    To leave a Group, first, click on "Leave Group" in the Group’s Info


    then, click on "Yes" under the warning message.



Spaces are a themed container that can hold any number of Channels. Think of a Space as a community center where people gather to discuss different topics in dedicated areas (named Channels).

Spaces Features

  • Each space has a unique name and topic. You may change both the name and the Topic by clicking on the relevant field in the Space’s settings.

  • Members can leave a space at any time.

  • Space Administrators can create new channels and invite new people to the space using the appropriate buttons.

Spaces UI

Spaces appear in a dedicated section of the Team Tab, which gives access to all Space-related features:

  • Creating a Space

    To create a new Space, click on the "New" button in the Team Tab, and select "New Space."


    then, enter the Space’s name and topic, select any users to invite and finally, click on "Save."


  • Leaving a Space

    To leave a Space, click on the "Leave Space" in the Space’s General Channel Info.

Participants can leave a space at any time, while a Space Administrator can only leave a space if there is at least one other Space Administrator.

Both need to be invited to join the space again, and former Space Administrators get invited as regular participants but can be granted Administrator rights again.

Space Settings

Its General Channel Info defines a Space’s settings (see below).

The Space’s creator is also the first Space Administrator and can grant the same rights to any other user by clicking on the crown icon in the appropriate entry of the participant list.


Only Space Administrators can invite new participants, create new channels, kick people, and delete channels within the space.


Channels are topic-defined areas inside of the same space. Those can contain any number of users, and unlike Groups, users can autonomously join any Channel in a Space they are in instead of being invited to it by a member.

Each new Space has a "General" channel automatically created within it, which defines the space’s properties (e.g., Title and Topic) and which all users automatically join when they join the Space.

Channels Features

  • A user in a Channel can chat with all of the others. All members of that channel can view all messages sent on the Channel.

  • A user in a Channel can start a video chat with all of the others. Channel video chats can be joined at any time by all members of the Channel.

Channnels UI

Channels appear in Spaces within the Team Tab and all of the Channel-related features are managed there, by:

  • Creating a Channel

    To create a new Channel, click on the "New" button, and select "New Channel."


    then select:

    1. the Space that should contain the Channel (mandatory)

    2. the Channel’s name (mandatory)

    3. the Channel’s topic (optional)

      finally, click on "Save."

  • Joining a Channel

    To join a Channel, click on the Channel label and then on "Join Channel."

  • Starting a Channel video chat

    To start a Channel video chat, click on the "Camera" icon on the Channel’s chat window.


    Any member of the Channel can join the call at any time by clicking on the same button.

  • Leaving a Channel

    To leave a Channel, first, click on the red "Leave Channel" entry in the Channel’s Info


Both normal users and Space Admins can leave a channel at any time and join it afterward.

File sharing

Users can easily share files via Team to Chats and Groups by dragging and dropping the files directly into the chat interface (both in the minichat and in the Teamtab) or by clicking the "paperclip" icon on the right of the message input field. Multiple files can be uploaded at once, and image files will show a preview of the file while other common filetypes will display a custom icon.

Clicking on a file within a chat window will download it to the local client using the browser’s own download interface.

Files shared via Team will be stored inside a protected root folder the sender’s Drive called Team sent files, thus counting towards the sender’s mailbox quota, and will remain available for download in the chat window for all participants until deleted from Drive by the sender.

Video Chat

Video Chat features are available in 1-to-1 chats, Groups, and Channels, allowing multiple people to communicate in real-time using a webcam and a headset, as well as allowing them to share their screen with all other attendees.

The WebRTC protocol is the foundation for this feature. WebRTC is a peer-to-peer auto-adaptive technology that allows clients to communicate directly without overloading the server. Call quality is automatically tweaked based on the available bandwidth, with the maximum quality being Full HD for both video and audio. When starting their first video chat, users need to grant their browser access permissions to their camera and microphone.

Video Chat UI


The video chat UI has three main areas:

  • The center displays video streams with a single (main) stream on the top and multiple secondary streams on the bottom. The total number depends on the screen’s resolution and window size.

  • On the left is the Group’s or Channel’s instant messaging chat. This chat is visible and entirely usable, and its history gets retained in the group’s or channel’s chat history.

  • On the bottom left appear the user’s video feed and controls (disable video, mute microphone, and share screen).

Users can disconnect from an ongoing video chat by pressing the "Hang up" button in their video stream’s frame on the bottom left of the screen. Whenever a video chat is on, users belonging to the Group or Channel of the video chat see a "Call in progress" message below the name of the Group or Channel and may join by clicking on the "Camera" icon in the chat.

Before entering any Video Chat, a pop-up will appear allowing to activate or disactivate both the sound and video feeds. This preference is always saved, and sound/video can be freely enabled or disabled during the call regardless of the choice.

Video Stream Control

Video streams are displayed in a "first come, first served" basis according to the connection order between the peers.

Every participant can mute their audio stream or stop their video stream.

Screen Sharing


When clicking on the Screen Share button, a pop-up window appears asking the user whether to share their entire screen or just a specific window. After choosing, the screen sharing feed replaces the user’s webcam feed for all participants.

Instant Meetings

Instant Meetings are one-shot Video Chats that can be attended by external users as well as internal users.

To create an Instant Meeting, click on the "New" button in the Team Tab and select Instant Meeting.

Then, fill in the attendee list by entering any internal or external email address in the text box and pressing enter to add it to the list. Once all attendees are added, press "Save" to send an email notification to all participants and start the Instant Meeting.

Instant Meeting UI

The Instant Meeting feature uses the very same UI as any internal Video Chat session.


Autocomplete in Team is split in two different categories: Internal Autocomplete and External autocomplete.

Internal autocomplete kicks in when selecting a target for 1-1 Chats, Group Chats, Spaces and Channels, while External autocomplete is only used for Instant Meeting attendees.

This can be changed by setting the teamCrossDomainSearchMode COS property to either local, extended or global using the zxsuite config [get/set/empty] CLI toolset.

  • local mode, in which Internal Autocomplete will draw its information from the GAL, while External autocomplete will draw its information from the user’s Contacts and GAL.

  • extended mode is a superset of local that also matches full email addresses of any user in the same infrastructure as internal users.

    • This allows to initiate a 1-1 Chat with or to add to a Group/Space/Channel any user that is on the same infrastructure but out of the GAL as long as the exact email address is entered.

  • global mode is a superset of extended that does not require an exact match on the email address to autocomplete users in the same infrastructure.

    • This allows to autocomplete any user in the infrastructure as opposed to the strict email addres match required in extended mode.


The default setting inherited by all COS is local.


Presence is managed automatically in Zextras Team: whenever a user logs in, regardless of whether the Team Tab has the focus, they appear as online.

As part of the user presence system, all messages get displayed with a variable number of check symbols:


  • 0 checks, message not delivered to the server

  • 1 check, message delivered to the server

  • 2 checks, message viewed by all users

Unread Messages

The number of unread messages in any conversation, Group or Channel appears on the right side of the conversation, Group, or Channel.


Edit, Reply, Forward and Delete Messages

Right clicking on a message or hovering on a message and clicking on the arrowhead that appears on the right side of the message bubble displays a context menu that shows the available actions:

  • Edit: change the message’s content. The "edited" string will appear next to the message delivery icon.

  • Reply: reply to a message. The reply will be in the same chat and will not be private

  • Forward: forward a message to another chat, group or channel.

  • Delete: delete a message. The message bubble’s color will change to gray and the "Deleted Message" string will appear instead of the original text.

The following table recaps all message interactions:


Can be edited

Can be deleted

Can be forwarded

Text Message

(Only own messages)

File Attachment message

(Only if description already exists)

Conversation Status message

Edited message

Forwarded message

Deleted message

Chat History

Chat History for each 1-to-1 Chat, Group, and Channel is available in the very same window (e.g., enter a Channel to see all of that channel’s history) and messages delivered to offline users appear in the appropriate IM conversation, Group or Channel.


Since WebRTC is a peer-to-peer protocol, all users in a video chat must be able to reach each other’s client for the connections to get established.

Should this not be possible, because of NAT rules on the network or because of a Service Provider’s policy, using a TURN server ensures proper communication between all peers. Zextras Team is designed to allow using a STUN/TURN server out of the box by simply adding the TURN server’s URL and login information in the zimlet configuration.

Setting up Zextras Team to use a TURN server

A dedicated set of TURN configuration tools is available via CLI through the zxsuite team iceServer command:

zimbra@mailserver:~$ zxsuite Team iceServer

Edit the list of ice servers which will be used to establish connections for video calls.
Configuration available for global(default), cos or account.

  add                      - add ice server candidates using global (default), cos or account
                             zxsuite Team iceServer add {turn:turn.example.com:3478?transport=udp} [attr1 value1 [attr2 value2...]]

  remove                   - remove ice server candidates using global (default), cos or account
                             zxsuite Team iceServer remove {turn:turn.example.com:3478?transport=udp} [attr1 value1 [attr2 value2...]]

  get                      - get ice server candidates using global (default), cos or account
                             zxsuite Team iceServer get [attr1 value1 [attr2 value2...]]

The "add" subcommand is used to add a new TURN server:

   zxsuite Team iceServer add {turn:turn.example.com:3478?transport=udp} [attr1 value1 [attr2 value2...]]


url(M)           String    turn:turn.example.com:3478?transport=udp
username(O)      String    myuser
credential(O)    String    mysecretkey
account(O)       String    user@example.com
cos(O)           String    default

(M) == mandatory parameter, (O) == optional parameter

Usage example:

zxsuite Team iceserver add turn:turn.example.com credential mysecret username myuser
zxsuite Team iceserver add turn:turn.example.com credential mysecret username myuser account testaccount@example.com

Multiple TURN servers can be added to handle different users or Classes of Service (defined through the user and cos optional parameters of the command above).

On the TURN server side, it is strongly recommended to have a single user, authenticated with a username and secret key, for ease-of-use reasons as a 1:1 correspondence between Zimbra users and TURN users is not necessary.