Mobilizon requires a SMTP server to deliver emails. Using 3rd-party mail providers (Mandrill, SendGrid, Mailjet, …) will be possible in the future.
## SMTP configuration
Mobilizon default settings assumes a SMTP server listens on `localhost`, port `25`. To specify a specific server and credentials, you can add the following section in your `prod.secret.exs` file and modify credentials to your needs.
# can be `:always`. If your smtp relay requires authentication set it to `:always`.
auth: :if_available
```
!!! tip
The hostname option sets the FQDN to the header of your emails, its optional, but if you don't set it, the underlying `gen_smtp` module will use the hostname of your machine, like `localhost`.
You'll need to restart Mobilizon to recompile the app and apply the new settings.