QNAP Systems, Inc. - Network Attached Storage (NAS)



Mattermost User Guide


Mattermost is an easy to use, simplified team communication and scalable enterprise messaging system. Mattermost is your team communication all in one place, instantly searchable and available anywhere. You can create your own privately hosted chat solution on your QNAP NAS.
Mattermost application offers the chance to keep all of your teams communications in one place, making it easier for everyone to discuss together within group or private chats. This can be done using the private and public channel feature of Mattermost, which is explained in this document later. This document also explains how to install and getting started with Mattermost.

System Requirements

  1. Mattermost is currently supported on X86 based NAS models only.
  2. QTS Version 4.3.3 and above.
  3. You need to enable port forwarding on your NAS to access Mattermost over the internet. CloudLink is not supported by Mattermost as of now.
  4. Supported languages: English, Spanish, French, Italian, Dutch, Polish, Portuguese, Turkish, Russian, Korean, Simplified Chinese, Traditional Chinese, Japanese


Go to “App Center”, search for Mattermost in the search bar.

And Click button below the Materrmost icon to install the Mattermost application.


Getting started:

Signing up

After installing, open the Mattermost application. The following window will pop up:

Enter your valid email address in the given field.
Enter a username of your choice, which will be displayed to other users using mattermost.
Enter a secure password and click on create account button below it.

Once you have created your account, click on” create a new team:”

You will be prompted to enter a team name, click next after you enter the name of your team you want to create.

You can also sign up and directly and join an already existing team using the team URL given by the admin. (The URL will be generated in next step).

An URL will be generated, which you can share with the members of your team, those you want to be in the team that you have created.

Once they receive the URL, they will be able to join your team and follow a similar signing up process.

You can edit the web address as per your choice and requirements, for sharing with the team.

Once you click finish, you will be taken to the messaging interface.
You can access and create channels.
You can choose whether to create a public channel or private.

Setting Your Status

When you click your avatar at the top of the channel list, a dropdown menu will appear. You can set your status as online, away, or offline by selecting a status from that menu.

Logging Out

You can log out from the Main Menu, which is accessed by clicking the three dash in the top header on the left side of the screen. When you click on Logout, you will be logged out of all teams on the server.


Channels organize conversations across different topics. They’re open to everyone on your team. To send private communications use Direct Messages for a single person or Private Channel for multiple people.

Click "More..." to create a new channel or join an existing one.
You can also create a new channel by clicking the "+" symbol next to the public or private channel header.

Channel Types

Mattermost has Channels feature to organize conversations across different topics.
There are three types of channels: Public Channels, Private Channels, and Direct Messages.

1. Public Channels

Public Channels are open to everyone on a team.
By default, new team members are automatically added to two Public Channels when they sign up: Town Square and Off-Topic.

2. Private Channels

Private Channels are for sensitive topics and are only visible to select team members. Any member of a Private Channel can add additional members. Channel members can choose to leave at any time, but only the channel owner or Team Admin can remove other members.

3. Direct Messages and Group Messages

Direct Messages are for conversations between two people. Group Messages are Direct Messages that have conversations among three or more people. Both are visible only to the people involved.
Use a Direct Message when you want a private conversation with one other person.

Group Message can be used when you want to quickly set up a conversation with up to seven other participants. If you want more than that, you must create a Private Channel.
If your System Administrator has allowed it, you can start a Direct Message or a Group Message with people on other teams, not just your own.

There is also an online status indicator next to the names in the Direct Message list. It displays: online (active browser), away (no browser activity for 5 minutes), and offline (browser closed).

Managing Channels

Channels can be created, joined, renamed, left and deleted.

Creating a Channel

Create a new Public Channel or Private Channel by selecting the symbol next to the Public Channels or Private Channels header on the left hand side. To start a direct message thread, click More at the bottom of the Direct Messages list to view a list of team members you can message. Anyone can create Public Channels or Private Channels, unless the System Administrator has restricted the permissions.

Joining a Channel

Click More at the bottom of the Channels list to view a list of Public Channels you can join. To join a Private Channel you need to be added by a member of that channel.

Adding Members to a Channel

Click the channel name at the top of the center pane to access the drop-down menu, then click ‘Add
Members.’ Any member of a channel can add new members by clicking ‘Add’ next to a user’s name. Users already added to the channel will not appear in this modal.

Removing Members from a Channel

Click the channel name at the top of the center pane to access the drop-down menu, and then click Manage Members. Any member of a channel can remove other members by clicking Remove next to a user’s name.

Renaming a Channel

Click the channel name at the top of the center pane to access the drop-down menu, and then click Rename Channel. Anyone can rename the channels they belong to, unless the System Administrator has restricted the permissions.
You may also change the channel URL (also known as the channel handle) when renaming a channel. Changing channel URL may break existing links.

Leaving a Channel

Click the channel name at the top of the center pane to access the drop-down menu, and then click ‘Leave Channel’. Any team member who leaves a Private Channel must be re-added by a channel member if they wish to rejoin. Team members will not receive mention notifications from channels of which they are not members.

Deleting a Channel

Click the channel name at the top of the center pane to access the drop-down menu, then click ‘Delete Channel.’
Anyone can delete the Public Channels or Private Channels they belong to, unless the System Administrator has restricted the permissions.
When a channel is deleted it is removed from the user interface, but an archived copy exists on the server in case it is needed for audit reasons later.

For this reason, the URL of a newly created channel cannot be the same URL name as a deleted channel.

Favoriting a Channel

Favorite channels are a great way to organize your sidebar by choosing which Channels, Private Channels, and Direct Messages are most important to you.

To mark a channel as a favorite, simply open the channel and then click the star  that appears to the left of the channel name


Send messages

You can write the message using the text input box at the bottom of Mattermost.

Press ENTER to send a message. Use SHIFT+ENTER to create a new line without sending a message.

Replying to messages

You can also reply to a particular message by clicking the reply arrow next to the message text.

You can comment and reply on a particular message, and a new thread pertaining to that message having all the replies and comments will be created and it will appear on the message chat interface.

Mentioning teammates

You can notify your teammates when they are needed by typing 

Type @ to bring up a list of team members who can be mentioned. To filter the list, type the first few letters of any username, first name, last name, or nickname. Use the UP and DOWN arrow keys to scroll through entries in the list, and then press ENTER to select the person to mention. When selected, the username replaces the full name or nickname.

The following example sends a special mention notification to Matthew, whose username is Matthew. The notification alerts her of the channel and message where she was mentioned.

If Mathew is away from Mattermost and has email notifications turned on, then she receives an email alert of her mention along with the message text.

If the person you mentioned does not belong to the channel, a System Message is posted to let you know. This is a temporary message, and you are the only one who can see it. To add the mentioned person to the channel, go to the dropdown menu beside the channel name and select Add Members.

@channel and @all
You can mention an entire channel by typing @channel or @all. All members of the channel receive a mention notification that behaves the same way as if the members had been mentioned personally. If used in Town Square, it notifies all members of your team.
@channel great work on interviews this week. I think we found some excellent potential candidates!
If a channel has five or more members, you are prompted to confirm that you want notifications sent to everyone in the channel.

You can mention everyone who is online in a channel by typing @here. This sends a desktop notification and push notification to members of the channel who are online. It’s counted as a mention in the sidebar. Members who are offline do not receive a notification, and when they come back to the site they will not see a mention counted in the channel sidebar. Members who are away receive a desktop notification only if they have notifications set to “all activity”, and they will not see a mention counted in the sidebar.
@here can someone do a quick review of this?

Words That Trigger Mentions
You can customize words that trigger mention notifications in ‘Account Settings > Notifications > Words that trigger mentions. By default, you receive mention notifications for your username and for @channel@all and @here. You can choose to have your first name be a word that triggers mentions.
You can add a list of customized words to get mention notifications for by typing them into the input box, separated by commas. This is useful if you want to be notified of all posts on certain topics, such as “interviewing” or “marketing”.

Recent Mentions
Click @ next to the search box to query for your most recent @mentions and words that trigger mentions. Click Jump next to a search result in the right-hand sidebar to jump the center pane to the channel and location of the message with the mention.

Sharing Files

The following types of files can be attached with a message in Mattermost:

  1. Images: BMP, GIF, JPG, JPEG, PNG, SVG
  2. Video: MP4
  3. Audio: MP3, M4A
  4. Files: PDF, TXT

How to Attach Files

You can attach files in the following ways:

  • Use the attachment icon - click the paperclip icon inside the message input box (right corner)
  • Drag and Drop
  • Paste from the clipboard

File Previewer

Mattermost has a built-in file previewer that you can use to:

  • Download files
  • Share public links
  • View media

Click the thumbnail of an attached file to open it in the file previewer.

Downloading Files
You can download an attached file by clicking the download icon next to the file thumbnail.

Sharing Public Links

Public URLs allow you to share attachments with anyone outside the Mattermost system. To share an attachment, click the thumbnail of an attachment, then click Get Public Link.
If Get Public Link is not visible in the file previewer and you prefer that the feature is enabled, you can request your System Admin to enable the feature from the System Console under Security > Public Links.

Note: Only a maximum of five attached files per post is supported by Mattermost, and maximum file size is 50 MB. Only a system administrator can increase the size allotted.

Flagging a message

You can flag a message, which you would want to follow up later.

To try it out, hover over a message to show the flag icon. Click the icon to flag the message for follow up.

Click the flag beside the search box to view a list of your flagged messages.

To remove an item from the flagged list, click the flag beside a message to clear it.

Pinning Messages

Any member of a channel can pin important or useful messages to that channel. The list of pinned messages is visible to all channel members.

Pinned messages are marked with the pinned icon

To pin a message:

  1. Mouse over the message that you want to pin. The [...] link appears.
  2. Click [...] > Pin to channel

To un-pin a message:

  1. Mouse over the message that you want to un pin. The [...] link appears.
  2. Click [...] > Un-pin from channel

Team management

If the System Admin has set ‘Enable Team Creation’ to true from the System Console, then new teams can be created by anyone.

If the System Admin enables team creation, teams can be created from the team sidebar or Main Menu. The team Admin for that team will be the person who created that team.

Click the icon at the bottom of the team sidebar, which will take you to the page where you can enter a team name and choose URL for your new team. If you are unable to see this option in the menu, then the System Admin has disabled team creation.

Main Menu

You can also create a team from the main menu, click on the Main Menu > Create a New Team.

If you are unable to see this option in the menu, then the System Admin has disabled team creation.

Managing members


If your System Admin has enabled adding, you can add people to your team in one of three ways: You can send a direct invite; you can share a public team invite link; or if they already have an account on the server, you can add them to the team yourself.

Direct invitation

The person will receive your invitation directly to their email address, which would be sent from your teams’ server directly. There will be a link within the invitation that will take them to an account creation page.

To send a direct invitation:

  1. At the top of the Navigation Panel, click your username.
  2. Click Send Email Invite and enter the person’s email address with their first and last name.
  3. To invite more than one person, click Add another and click Send Invitation.

Team Invite Link

The team invite link is a unique URL that directs people to an account creation page for a team. A team invite link can be used by anyone and does not change unless it is re-generated by a Team Admin or System Admin via Team Settings > General > Invite Code. For example, the team invite link can be included in a company wide email to invite all employees to join a Mattermost team.

To get a team invite link:

  1. Click your username, at the top of the Navigation Panel.
  2. Click Get Team Invite Link.
  3. In the window that opens, copy the link and share it with those you want to invite to the team.

Adding Someone to Your Team

If someone you want to add to your team already has an account on the server, you can add them to your team without sending an invitation.

To add someone to your team:

  1. Click your username, at the top of the Navigation Panel.
  2. Click Add Members to Team. The Add New Members window opens.
  3. Click the username of the person or people to add to your team. You can type in the search box to filter the list. If the people you want to add are not on the list, then they are either already on your team or they do not have an account on your server.


There are four types of user roles with different permission levels in Mattermost:
System Admins, Team Admins, Members, and Inactive accounts. To view a list of users on the team and what their roles are, Team Administrators can go to the [...] Main Menu and select Manage Members.


When a user join a team, this is the default role given to them. Members are given the basic permissions on the Mattermost team.

Channel Admin

The creator of the channel is assigned the Channel Admin role for that channel. People with the Channel Admin role are able to do the following:

  • Assign the Channel Admin role to other members of the channel.
  • Remove the Channel Admin role from other holders of the Channel Admin role.
  • Remove members from the channel.

Special permissions by the System Admin to rename and delete channels is granted to channel Admins, depending on the system configuration.

Team Admin

On creation of the team, the person who set it up is made a Team Administrator. Someone can be a Team Admin for one team but only a Member on another team. Team Administrators have access and are able to do the following:

  • “Team Settings” menu from the team site main menu
  • Change the team name and import data from Slack export files
  • “Manage Members” menu, where they can control whether team members are “Members” or “Team Administrators”

System Admin

The first user added to a newly installed Mattermost system is assigned the System Admin role.
The System Admin is typically a member of the IT staff and has all the privileges of a Team Admin, and is able to do and access the following:

  • System Console from the main menu in any team site
  • Change any setting on the Mattermost server available in the System Console
  • Promote and demote other users to and from the System Admin role
  • Deactivate user accounts and to reactivate them
  • Private channels, but only if given the link to the private channel

Removing a User from a Team or Leaving a Team

Remove from Team

Any Team Administrator has the ability to remove a user from a team by going to the [...] Main Menu > Manage Members, and selecting Remove From Team in the dropdown menu beside a user entry.

When a user is removed from a team, the team will no longer show up in their team sidebar. If they currently have the team open, they are redirected to the first team that appears on their team sidebar. If they didn’t belong to any other teams, the user is sent to the team selection page.

A System Administrator can also remove users from teams by going to System Console > Users, and selecting the dropdown beside a user entry and clicking Manage Teams.

Leaving a Team

Users can also choose to remove themselves from a team, by going to the [...] Main Menu > Leave Team. This will remove the user from the team, and from all public channels and private channels on the team.
They will only be able to rejoin the team if it is set to “Allow any user with an account on this server to join this team” team, or if they receive a new invite. If they do rejoin, they will no longer be a part of their old channels.

System Console

You can go to the system Console from Main Menu > System Consol

Email Notifications:

Under the Notifications tab on the left side of the System Console menu, click on ‘Email’

You can set up the email notifications to either true or false as per your requirement.

You need to have a SMTP email server setup first in order to enable email notifications

Steps for SMTP Email Setup

To run in production, Mattermost requires SMTP email to be enabled for email notifications and password reset for systems using email-based authentication.

How to Enable Email

To enable email, configure an SMTP email service as follows:

  1. Set up an SMTP email sending service (if you don’t yet have an SMTP service with credentials)
    • Any SMTP email service can be used, you just need the following information: Server Name, Port, SMTP Username, and SMTP Password.
      • If you don’t have an SMTP service, here are simple instructions to set one up with Amazon Simple Email Service (SES):
        1. Go to Amazon SES console then SMTP Settings > Create My SMTP Credentials
        2. Copy the Server Name, Port, SMTP Username, and SMTP Password for Step 2 below.
        3. From the Domains menu set up and verify a new domain, then enable GenerateDKIM Settings for the domain.
          • Mattermost recommends to set up Sender Policy Framework (SPF) and/or Domain Keys Identified Mail (DKIM) for your email domain.
          • Choose an sender address like mattermost@example.com and click Send a TestEmail to verify setup is working correctly.
  2. Configure SMTP Settings
    • Open the System Console by logging into an existing team and accessing “System Console” from the main menu.

      Alternatively, if a team doesn’t yet exist, go to http://dockerhost:8065/ in your browser, create a team, then from the main menu click System Console
    • Go to the Authentication > Email tab and configure the following:
      Allow Sign Up With Email: true
    • Go to the Notifications > Email tab and configure the following:
      • Send Email Notifications: true
      • Notification Display Name: Display name on email account sending notifications
      • Notification Email Address: Email address displayed on email account used to send notifications
      • SMTP Username: SMTP Username from Step 1
      • SMTP Password: SMTP Password from Step 1
      • SMTP Server: SMTP Server from Step 1
      • SMTP Port: SMTP Port from Step 1
      • Connection Security: TLS (Recommended)
      • Then click Save
      • Then click Test Connection
      • If the test failed please look in OTHER > Logs for any errors that look like [EROR]/api/v3/admin/test_email ...

Sample SMTP Settings

Amazon SES

  • Set SMTP Username to [YOUR_SMTP_USERNAME]
  • Set SMTP Password to [YOUR_SMTP_PASSWORD]
  • Set SMTP Server to email-smtp.us-east-1.amazonaws.com
  • Set SMTP Port to 465
  • Set Connection Security to TLS


  • Make sure Postfix is installed on the machine where Mattermost is installed
  • Set SMTP Username to (empty)
  • Set SMTP Password to (empty)
  • Set SMTP Server to localhost
  • Set SMTP Port to 25
  • Set Connection Security to (empty)


  • Set SMTP Username to your_email@gmail.com
  • Set SMTP Password to your_password
  • Set SMTP Server to smtp.gmail.com
  • Set SMTP Port to 587
  • Set Connection Security to STARTTLS


  • Set SMTP Username to your_email@hotmail.com
  • Set SMTP Password to your_password
  • Set SMTP Server to smtp-mail.outlook.com
  • Set SMTP Port to 587
  • Set Connection Security to STARTTLS

Once you have setup the SMTP server, Click ‘save’ before exiting the system console.

Team statistics and Site Statistics

You can view the detailed team statistics under the REPORTING tab, where you can find all the details regarding total users, total posts, number of channels, number of teams, and daily and monthly active users.

Release date: 2017-11-15
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