Only use this option if you know what you're doing.

If you decide you want to check out or edit the Dovecot configuration file by hand, you can do so by pressing the Edit Config File button. You will then be taken to a screen with a window containing your dovecot.conf file.

There are options in the config file that are not in the Webmin tool, but only edit those options if you are sure how to do so.

The final step is to deal with startup. Press the Start Dovecot Server button to start the server manually. If you choose to use this method every time your server reboots (should that ever happen), you must remember to log back in to Webmin and start the server. I would recommend selecting the Yes check box and pressing the Start at boot button, in order to have Dovecot start at boot.

Your server is ready to serve mail.

Final thoughts
Linux has come a long way. With these types of tools, setting up a reliable e-mail server is now as simple as point, click, and start. SuSE would do itself a favor by adding POP/IMAP server configuration into its robust YaST toolset. However, for the time being, using Webmin to set up a mail server is just as simple as it would be under the SuSE tool.