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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or 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

Also available in legacy Mattermost Enterprise Edition E10 or E20

The maximum amount of time, in seconds, allowed for establishing a TCP connection between Mattermost and the SMTP server.

Numerical value in seconds.

  • System Config path: Environment > SMTP

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

  • Environment variable: MM_EMAILSETTINGS_SMTPSERVERTIMEOUT