action/drawable-anydpi-v21/ic_markunread_mailbox_black_24dp.xml

<vector xmlns:android="http://schemas.android.com/apk/res/android"
        android:width="24dp"
        android:height="24dp"
        android:viewportWidth="24.0"
        android:viewportHeight="24.0">
    <path
        android:fillColor="#FF000000"
        android:pathData="M20,6H10v6H8V4h6V0H6v6H4c-1.1,0 -2,0.9 -2,2v12c0,1.1 0.9,2 2,2h16c1.1,0 2,-0.9 2,-2V8c0,-1.1 -0.9,-2 -2,-2z"/>
</vector>