You can only have it to post to one page per category and you just fill in the mobile email address for the page to post to next to the category in the settings page.
Setup instructions
To use this plugin you need to have a page at Facebook for your company, brand, band, cause, topic or whater you want. Pages can be created at
this page.
Once you have the page setup you can go to "Edit page" > "Mobile" and there you see your secret email address. It should be something like [Random characters]@m.facebook.com.
You can specify one email address per category. If you would like to post only to one page no matter how many categries you have you just specify the same email address in all fields. In that case only ONE email will be sent. If you have one email for Category A and another email for Category B and the post you publish got both categories, two emails will be sent (one to each page). You can read more about this at
the plugin page.