# Email 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. ```elixir config :mobilizon, Mobilizon.Web.Email.Mailer, adapter: Bamboo.SMTPAdapter, server: "localhost", hostname: "localhost", port: 25, username: nil, password: nil, # can be `:always` or `:never` tls: :if_available, allowed_tls_versions: [:tlsv1, :"tlsv1.1", :"tlsv1.2"], # can be `true` ssl: false, retries: 1, # can be `true` no_mx_lookups: false, # 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.