k-9/res/xml/font_preferences.xml

<?xml version="1.0" encoding="utf-8"?>

<!--
  Make sure to add android:persistent="false" to all preferences to disable saving
  the preference values to SharedPreferences. We use our own storage mechanism for
  the preferences. See com.fsck.k9.preferences.Storage.

  Also note that every sub-PreferenceScreen needs an "android:key" parameter so the correct screen
  can be displayed after the device has been rotated.
-->

<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">

    <PreferenceScreen
        android:title="@string/font_size_account_list"
        android:key="account_list_fonts">

        <ListPreference
            android:persistent="false"
            android:key="account_name_font"
            android:title="@string/font_size_account_name"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_account_name" />

        <ListPreference
            android:persistent="false"
            android:key="account_description_font"
            android:title="@string/font_size_account_description"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_account_description" />

    </PreferenceScreen>

    <PreferenceScreen
        android:title="@string/font_size_folder_list"
        android:key="folder_list_fonts">

        <ListPreference
            android:persistent="false"
            android:key="folder_name_font"
            android:title="@string/font_size_folder_name"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_folder_name" />

        <ListPreference
            android:persistent="false"
            android:key="folder_status_font"
            android:title="@string/font_size_folder_status"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_folder_status" />

    </PreferenceScreen>

    <PreferenceScreen
        android:title="@string/font_size_message_list"
        android:key="message_list_fonts">

        <ListPreference
            android:persistent="false"
            android:key="message_list_subject_font"
            android:title="@string/font_size_message_list_subject"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_list_subject" />

        <ListPreference
            android:persistent="false"
            android:key="message_list_sender_font"
            android:title="@string/font_size_message_list_sender"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_list_sender" />

        <ListPreference
            android:persistent="false"
            android:key="message_list_date_font"
            android:title="@string/font_size_message_list_date"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_list_date" />

        <ListPreference
            android:persistent="false"
            android:key="message_list_preview_font"
            android:title="@string/font_size_message_list_preview"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_list_preview" />

    </PreferenceScreen>

    <PreferenceScreen
        android:title="@string/font_size_message_view"
        android:key="message_view_fonts">

        <ListPreference
            android:persistent="false"
            android:key="message_view_sender_font"
            android:title="@string/font_size_message_view_sender"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_view_sender" />

        <ListPreference
            android:persistent="false"
            android:key="message_view_to_font"
            android:title="@string/font_size_message_view_to"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_view_to" />

        <ListPreference
            android:persistent="false"
            android:key="message_view_cc_font"
            android:title="@string/font_size_message_view_cc"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_view_cc" />

        <ListPreference
            android:persistent="false"
            android:key="message_view_subject_font"
            android:title="@string/font_size_message_view_subject"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_view_subject" />

        <ListPreference
            android:persistent="false"
            android:key="message_view_date_font"
            android:title="@string/font_size_message_view_date"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_view_date" />

        <ListPreference
            android:persistent="false"
            android:key="message_view_additional_headers_font"
            android:title="@string/font_size_message_view_additional_headers"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_view_additional_headers" />

        <com.fsck.k9.activity.setup.SliderPreference
            android:persistent="false"
            android:key="message_view_content_font_slider"
            android:title="@string/font_size_message_view_content"
            android:dialogTitle="@string/font_size_message_view_content" />

    </PreferenceScreen>

    <PreferenceScreen
        android:title="@string/font_size_message_compose"
        android:key="message_compose_fonts">

        <ListPreference
            android:persistent="false"
            android:key="message_compose_input_font"
            android:title="@string/font_size_message_compose_input"
            android:entries="@array/font_entries"
            android:entryValues="@array/font_values"
            android:dialogTitle="@string/font_size_message_compose_input" />

    </PreferenceScreen>

</PreferenceScreen>