Configure SMTP email server settings by going to System Console > Environment > SMTP, or by editing the config.json file as described in the following tables.

SMTP server 

Available in legacy Enterprise Edition E10/E20

The location of the SMTP email server used for email notifications.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.SMTPServer",

  • Environment variable: MM_EMAILSETTINGS_SMTPSERVER

SMTP server port 

Available in legacy Enterprise Edition E10/E20

The port of SMTP email server.

Numerical input.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.SMTPPort",

  • Environment variable: MM_EMAILSETTINGS_SMTPPORT

Enable SMTP authentication 

Available in legacy Enterprise Edition E10/E20

Enable or disable SMTP authentication.

  • true: SMTP username and password are used for authenticating to the SMTP server.

  • false: (Default) Mattermost doesn’t attempt to authenticate to the SMTP server.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.EnableSMTPAuth": false",

  • Environment variable: MM_EMAILSETTINGS_ENABLESMTPAUTH

SMTP server username 

Available in legacy Enterprise Edition E10/E20

The username for authenticating to the SMTP server.

String input.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.SMTPUsername",

  • Environment variable: MM_EMAILSETTINGS_SMTPUSERNAME

SMTP server password 

Available in legacy Enterprise Edition E10/E20

The password associated with the SMTP username.

String input.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.SMTPPassword",

  • Environment variable: MM_EMAILSETTINGS_SMTPPASSWORD

SMTP connection security 

Available in legacy Enterprise Edition E10/E20

Specify connection security for emails sent using SMTP.

  • Not specified: (Default) Send email over an unsecure connection.

  • TLS: Communication between Mattermost and your email server is encrypted.

  • STARTTLS: Attempts to upgrade an existing insecure connection to a secure connection using TLS.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.ConnectionSecurity",

  • Environment variable: MM_EMAILSETTINGS_CONNECTIONSECURITY

Skip server certificate verification 

Available in legacy Enterprise Edition E10/E20

Configure Mattermost to skip the verification of the email server certificate.

  • true: Mattermost won’t verify the email server certificate.

  • false: (Default) Mattermost verifies the email server certificate.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.SkipServerCertificateVerification": false",

  • Environment variable: MM_EMAILSETTINGS_SKIPSERVERCERTIFICATEVERIFICATION

Enable security alerts 

Available in legacy Enterprise Edition E10/E20

Enable or disable security alerts.

  • true: (Default) System Admins are notified by email if a relevant security fix alert is announced. Requires email to be enabled.

  • false: Security alerts are disabled.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.EnableSecurityFixAlert": true",

  • Environment variable: MM_EMAILSETTINGS_ENABLESECURITYFIXALERT

See the Telemetry documentation to learn more.

SMTP server timeout 

Available in legacy Enterprise Edition E10/E20

The maximum amount of time, in seconds, allowed for establishing a TCP connection between Mattermost and the SMTP server to be idle before being terminated.

Numerical value in seconds.

  • System Config path: Environment > SMTP

  • config.json setting: ".EmailSettings.SMTPServerTimeout",

  • Environment variable: MM_EMAILSETTINGS_SMTPSERVERTIMEOUT