* `adapter`: one of the mail adapters listed in [Swoosh readme](https://github.com/swoosh/swoosh#adapters), or `Swoosh.Adapters.Local` for in-memory mailbox.
* `api_key` / `password` and / or other adapter-specific settings, per the above documentation.
An example for Sendgrid adapter:
```exs
* `adapter`: one of the mail adapters listed in [Swoosh readme](https://github.com/swoosh/swoosh#adapters), or `Swoosh.Adapters.Local` for in-memory mailbox.
* `api_key` / `password` and / or other adapter-specific settings, per the above documentation.
An example for Sendgrid adapter:
```exs