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Mailtrain App


Mailtrain is a self hosted newsletter app.

VERP handling

VERP is a feature where bounces are sent back to special addresses. Mailtrain supports VERP and can be configured to process these bounces and automatically unsubscribe addresses that are bouncing.

On the Cloudron, VERP handling is disabled because Cloudron's mail server does not support it. We plan to add this feature in a future release. Rest assured, Mailtrain can be used without any issue when VERP is not setup.

For now, bounces are sent to the Email "reply-to" address in the campaign and have to be processesed manually.

Changing Email "from" Address

Cloudron's email server does not allow apps to send emails with arbitrary FROM addresses. This is a simple security measure that prevents apps from unintentionally sending out emails that they are not supposed to send.

Cloudron assigns address by default to apps. To change this email address, follow the instructions here.

External mail server

To revert from an external email server setup to the Cloudron setup, set the SMTP Hostname to localhost and then restart the app. This will inject the Cloudrons SMTP credentials automatically.


Additional settings can be added to /app/data/production.toml using the File manager.