To enable the [fetchmail](http://www.fetchmail.info) service to retrieve e-mails set the environment variable `ENABLE_FETCHMAIL` to `1`. Your `docker-compose.yml` file should look like following snippet:
A detailed description of the configuration options can be found in the [online version of the manual page](http://www.fetchmail.info/fetchmail-man.html).
__IMPORTANT__: Don’t forget the last line: e. g. `is 'user1@domain.tld'`. After `is` you have to specify one email address from the configuration file `config/postfix-accounts.cf`.
More details how to configure fetchmail can be found in the [fetchmail man page in the chapter “The run control file”](http://www.fetchmail.info/fetchmail-man.html#31).
## Polling interval
By default the fetchmail service searches very 5 minutes for new mails on your external mail accounts. You can override this default value by adding this line to your `fetchmail.cf`.
```
set daemon 60
```
You must specify a numeric argument which is a polling interval in seconds. The example above polls every minute for new mails.
For more informations about the configuration script `setup.sh` [[read the corresponding wiki page|Setup-docker-mailserver-using-the-script-setup.sh]].