All integrations Messaging

Mattermost + MailKite

Mattermost is an open-source messaging platform for teams. Point its SMTP at MailKite and every invite, notification, and password reset goes out over your own DKIM-signed domain.

What you need

A verified domain with SPF + DKIM published
Your API key (mk_live_…)
Mattermost instance (self-hosted or cloud)

Configure SMTP

Open the System Console and navigate to Environment → SMTP. Enter the MailKite SMTP connection details.

SMTP Host	`smtp.mailkite.dev`
SMTP Port	`587`
Encryption	TLS (STARTTLS)
Username	`mailkite`
Password	Your API key (`mk_live_…`)
From Address	`hello@yourdomain.com` (on a verified domain)

System Console → Environment → SMTP

# System Console → Environment → SMTP

SMTP Server:            smtp.mailkite.dev:587
Connection Security:    TLS
SMTP Username:          mailkite
SMTP Password:          mk_live_...
Feedback Email:         hello@yourdomain.com
Reply-To Address:       hello@yourdomain.com

Test it

Invite a new user or trigger a password reset email. Check your MailKite dashboard to confirm the message was relayed successfully.

Troubleshooting

Emails not sending — confirm the Feedback Email is on a verified domain.
535 Authentication failed — your password must be your mk_live_… API key, not a separate SMTP password.
Notifications disabled — ensure Enable Email Notifications is On under System Console → Site Configuration → Email.
Mattermost Cloud — configure SMTP in the admin console; the interface may differ slightly from self-hosted.

See the SMTP relay docs for the full connection reference, or all integrations for other platforms.