SMTP Email Setup¶

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

How to Enable Email¶

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

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):
    
    Go to Amazon SES console then SMTP Settings > Create My SMTP Credentials
    
    Copy the Server Name, Port, SMTP Username, and SMTP Password for Step 2 below.
    
    From the Domains menu set up and verify a new domain, then enable Generate DKIM Settings for the domain.
    
    We recommend you 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 Test Email to verify setup is working correctly.
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/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

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 TLS

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

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/platform 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
```