Jenkins + MailKite

Jenkins is the most popular open-source CI/CD server. Point its SMTP at MailKite and every build notification, failure alert, and approval request goes out over your own DKIM-signed domain.

What you need

• A verified domain with SPF + DKIM published
• Your API key (mk_live_…)
• Jenkins instance with the Email Extension plugin installed

Configure SMTP

Go to Manage Jenkins → System and scroll to Extended E-mail Notification. Enter the MailKite SMTP details. Also set the system admin email under Jenkins Location.

# Manage Jenkins → System → Extended E-mail Notification

SMTP server:        smtp.mailkite.dev
SMTP port:          587
Use SSL:            No
Use TLS:            Yes
Credentials:        mailkite / mk_live_...
Default user e-mail suffix: @yourdomain.com
Default Content Type:       text/html

# Also set under "Jenkins Location":
System Admin e-mail address: admin@yourdomain.com

Test it

Trigger a build and check the email notification, or use the "Test e-mail recipient" field in the Extended E-mail Notification settings to send a test message.

Troubleshooting

• Emails not sending — confirm the From address is on a verified domain.
• 535 Authentication failed — your password must be your mk_live_… API key, not a separate SMTP password.
• Email Extension plugin — install it from Manage Jenkins → Plugins if not already present. The built-in "E-mail Notification" section is less configurable.
• Use TLS, not SSL — make sure Use SSL is unchecked and Use TLS is checked for port 587.

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