diff --git a/legacy/core/src/main/java/com/fsck/k9/helper/MessageHelper.kt b/legacy/core/src/main/java/com/fsck/k9/helper/MessageHelper.kt
index ef56c5c0df5..abadd5ea92f 100644
--- a/legacy/core/src/main/java/com/fsck/k9/helper/MessageHelper.kt
+++ b/legacy/core/src/main/java/com/fsck/k9/helper/MessageHelper.kt
@@ -153,10 +153,10 @@ class MessageHelper(
                 }
             }
             val personal = address.personal
-            return if (!personal.isNullOrEmpty() && !isSpoofAddress(personal)) {
-                personal
-            } else {
-                address.address
+            return when {
+                personal.isNullOrEmpty() -> address.address
+                isSpoofAddress(personal) -> "$personal <${address.address}>"
+                else -> personal
             }
         }
 
diff --git a/legacy/core/src/test/java/com/fsck/k9/helper/MessageHelperTest.kt b/legacy/core/src/test/java/com/fsck/k9/helper/MessageHelperTest.kt
index dd0f46e5fc7..b10088bd851 100644
--- a/legacy/core/src/test/java/com/fsck/k9/helper/MessageHelperTest.kt
+++ b/legacy/core/src/test/java/com/fsck/k9/helper/MessageHelperTest.kt
@@ -133,7 +133,7 @@ class MessageHelperTest : RobolectricTest() {
     }
 
     @Test
-    fun toFriendly_spoofPreventionOverridesPersonal() {
+    fun toFriendly_spoofPreventionExpandsToShowBothPersonalAndAddress() {
         val address = Address("test@testor.com", "potus@whitehouse.gov")
         val friendly =
             toFriendly(
@@ -143,7 +143,21 @@ class MessageHelperTest : RobolectricTest() {
                 messageListPreferencesManager.getConfig().contactNameColor,
                 contactRepository,
             )
-        assertThat(friendly).isEqualTo("test@testor.com")
+        assertThat(friendly).isEqualTo("potus@whitehouse.gov <test@testor.com>")
+    }
+
+    @Test
+    fun toFriendly_firefoxRelayAddressShowsOriginalSenderAndRelayAddress() {
+        val address = Address("alias123@mozmail.com", "sender@example.com [via Relay]")
+        val friendly =
+            toFriendly(
+                address,
+                messageListPreferencesManager.getConfig().isShowCorrespondentNames,
+                messageListPreferencesManager.getConfig().isChangeContactNameColor,
+                messageListPreferencesManager.getConfig().contactNameColor,
+                contactRepository,
+            )
+        assertThat(friendly).isEqualTo("sender@example.com [via Relay] <alias123@mozmail.com>")
     }
 
     @Test
diff --git a/legacy/ui/legacy/src/main/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatter.kt b/legacy/ui/legacy/src/main/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatter.kt
index 8181886ad26..a0ee92065ac 100644
--- a/legacy/ui/legacy/src/main/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatter.kt
+++ b/legacy/ui/legacy/src/main/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatter.kt
@@ -61,9 +61,9 @@ internal class RealMessageViewRecipientFormatter(
     }
 
     private fun buildDisplayName(address: Address): CharSequence {
-        return address.personal?.takeIf {
-            it.isNotBlank() && !it.equals(meText, ignoreCase = true) && !isSpoofAddress(it)
-        } ?: address.address
+        val personal = address.personal?.takeIf { it.isNotBlank() && !it.equals(meText, ignoreCase = true) }
+            ?: return address.address
+        return if (isSpoofAddress(personal)) "$personal <${address.address}>" else personal
     }
 
     private fun isSpoofAddress(displayName: String): Boolean {
diff --git a/legacy/ui/legacy/src/test/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatterTest.kt b/legacy/ui/legacy/src/test/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatterTest.kt
index ad2d08b17b7..70b079227c9 100644
--- a/legacy/ui/legacy/src/test/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatterTest.kt
+++ b/legacy/ui/legacy/src/test/java/com/fsck/k9/ui/messageview/MessageViewRecipientFormatterTest.kt
@@ -152,7 +152,7 @@ class MessageViewRecipientFormatterTest : RobolectricTest() {
     }
 
     @Test
-    fun `do not show display name that looks like an email address`() {
+    fun `spoof prevention expands to show both display name and actual address`() {
         val recipientFormatter = createRecipientFormatter()
 
         val displayName = recipientFormatter.getDisplayName(
@@ -160,7 +160,19 @@ class MessageViewRecipientFormatterTest : RobolectricTest() {
             account,
         )
 
-        assertThat(displayName).isEqualTo("mallory@domain.example")
+        assertThat(displayName).isEqualTo("potus@whitehouse.gov <mallory@domain.example>")
+    }
+
+    @Test
+    fun `firefox relay address shows original sender and relay address`() {
+        val recipientFormatter = createRecipientFormatter()
+
+        val displayName = recipientFormatter.getDisplayName(
+            Address("alias123@mozmail.com", "sender@example.com [via Relay]"),
+            account,
+        )
+
+        assertThat(displayName).isEqualTo("sender@example.com [via Relay] <alias123@mozmail.com>")
     }
 
     @Test