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 Generate DKIM Settings for the domain.
          1. We recommend you set up Sender Policy Framework (SPF) and/or Domain Keys Identified Mail (DKIM) for your email domain.
        4. Choose an sender address like mattermost@example.com and click Send a Test Email to verify setup is working correctly.
  2. Configure SMTP settings
    1. 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
    2. Go to the Authentication > Email tab and configure the following:
      1. Allow Sign Up With Email: true
    3. Go to the Notifications > Email tab and configure the following:
      1. Send Email Notifications: true
      2. Notification Display Name: Display name on email account sending notifications
      3. Notification Email Address: Email address displayed on email account used to send notifications
      4. SMTP Username: SMTP Username from Step 1
      5. SMTP Password: SMTP Password from Step 1
      6. SMTP Server: SMTP Server from Step 1
      7. SMTP Port: SMTP Port from Step 1
      8. Connection Security: TLS (Recommended)
      9. Then click Save
      10. Then click Test Connection
      11. If the test failed please look in OTHER > Logs for any errors that look like [EROR] /api/v4/email/test ...

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

Postfix

  • 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)

Gmail

  • 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

Hotmail

  • 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

Office365 / Outlook

  • Set SMTP Username to your_email@hotmail.com
  • Set SMTP Password to your_password
  • Set SMTP Server Name to smtp.office365.com
  • Set SMTP Port to 587
  • Set Connection Security to STARTTLS

Troubleshooting SMTP

TLS/STARTTLS Requirements

If you fill in SMTP Username and SMTP Password then you must set Connection Security to TLS or to STARTTLS

Troubleshooting using Logs

If you have issues with your SMTP install, from your Mattermost team site go to the main menu and open System Console -> Logs to look for error messages related to your setup. You can do a search for the error code to narrow down the issue. Sometimes ISPs require nuanced setups for SMTP and error codes can hint at how to make the proper adjustments.

For example, if System Console -> Logs has an error code reading:

Connection unsuccessful: Failed to add to email address - 554 5.7.1 <unknown[IP-ADDRESS]>: Client host rejected: Access denied

Search for 554 5.7.1 error and Client host rejected: Access denied.

Checking your SMTP server is reachable

  • Attempt to telnet to the email service to make sure the server is reachable.

  • You must run the following commands from the same machine or virtual instance where mattermost/bin/mattermost is located. So if you’re running Mattermost from Docker you need to docker exec -ti mattermost-dev /bin/bash

  • Telnet to the email server with telnet mail.example.com 25. If the command works you should see something like

    Trying 24.121.12.143...
    Connected to mail.example.com.
    220 mail.example.com NO UCE ESMTP
    
  • Then type something like HELO <your mail server domain>. If the command works you should see something like

    250-mail.example.com NO UCE
    250-STARTTLS
    250-PIPELINING
    250 8BITMIME
    

Note

For additional troubleshooting tips, see the troubleshooting guide. To submit an improvement or correction, click Edit at the top of this page.