FairEmail/app/src/main/res/layout/message_header.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/tvAddress"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="6dp"
        android:layout_marginStart="6dp"
        android:maxLines="1"
        android:text="From"
        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
        app:layout_constraintEnd_toStartOf="@+id/tvTime"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/tvTime"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="6dp"
        android:maxLines="1"
        android:text="Time"
        android:textAppearance="@style/TextAppearance.AppCompat.Small"
        app:layout_constraintBottom_toBottomOf="@id/tvAddress"
        app:layout_constraintEnd_toEndOf="parent" />

    <TextView
        android:id="@+id/tvSubject"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="6dp"
        android:layout_marginStart="6dp"
        android:maxLines="1"
        android:text="Subject"
        android:textAppearance="@style/TextAppearance.AppCompat.Small"
        app:layout_constraintEnd_toStartOf="@+id/tvCount"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/tvAddress" />

    <TextView
        android:id="@+id/tvCount"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="6dp"
        android:maxLines="1"
        android:text="3"
        android:textAppearance="@style/TextAppearance.AppCompat.Small"
        app:layout_constraintBottom_toBottomOf="@id/tvSubject"
        app:layout_constraintEnd_toEndOf="parent" />

    <View
        android:id="@+id/vSeparator"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:layout_marginTop="6dp"
        android:background="?attr/colorSeparator"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/tvSubject" />
</android.support.constraint.ConstraintLayout>