diff --git a/msg_test.go b/msg_test.go
index b353558..b50edf9 100644
--- a/msg_test.go
+++ b/msg_test.go
@@ -4832,6 +4832,46 @@ func TestMsg_EmbedFile(t *testing.T) {
 	})
 }
 
+func TestMsg_EmbedReader(t *testing.T) {
+	t.Run("EmbedReader with file", func(t *testing.T) {
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		file, err := os.Open("testdata/embed.txt")
+		if err != nil {
+			t.Fatalf("failed to open file: %s", err)
+		}
+		t.Cleanup(func() {
+			if err := file.Close(); err != nil {
+				t.Errorf("failed to close file: %s", err)
+			}
+		})
+		if err = message.EmbedReader("embed.txt", file); err != nil {
+			t.Fatalf("failed to embed reader: %s", err)
+		}
+		embeds := message.GetEmbeds()
+		if len(embeds) != 1 {
+			t.Fatalf("failed to retrieve embeds list")
+		}
+		if embeds[0] == nil {
+			t.Fatal("expected embed to be not nil")
+		}
+		if embeds[0].Name != "embed.txt" {
+			t.Errorf("expected embed name to be %s, got: %s", "embed.txt", embeds[0].Name)
+		}
+		messageBuf := bytes.NewBuffer(nil)
+		_, err = embeds[0].Writer(messageBuf)
+		if err != nil {
+			t.Errorf("writer func failed: %s", err)
+		}
+		got := strings.TrimSpace(messageBuf.String())
+		if !strings.EqualFold(got, "This is a test embed") {
+			t.Errorf("expected message body to be %s, got: %s", "This is a test embed", got)
+		}
+	})
+}
+
 /*
 // TestNewMsgWithMiddleware tests WithMiddleware
 
diff --git a/msg_unix_test.go b/msg_unix_test.go
index ae4d018..0200470 100644
--- a/msg_unix_test.go
+++ b/msg_unix_test.go
@@ -177,6 +177,144 @@ func TestMsg_AttachReadSeeker_unixOnly(t *testing.T) {
 	})
 }
 
+func TestMsg_EmbedFile_unixOnly(t *testing.T) {
+	t.Run("EmbedFile with fileFromFS fails on open", func(t *testing.T) {
+		if os.Getenv("PERFORM_UNIX_OPEN_WRITE_TESTS") != "true" {
+			t.Skipf("PERFORM_UNIX_OPEN_WRITE_TESTS variable is not set. Skipping unix open/write tests")
+		}
+
+		tempFile, err := os.CreateTemp("testdata/tmp", "embedfile-open-write-test.*.txt")
+		if err != nil {
+			t.Fatalf("failed to create temp file: %s", err)
+		}
+		t.Cleanup(func() {
+			if err := os.Remove(tempFile.Name()); err != nil {
+				t.Errorf("failed to remove temp file: %s", err)
+			}
+		})
+		if err = os.Chmod(tempFile.Name(), 0o000); err != nil {
+			t.Fatalf("failed to chmod temp file: %s", err)
+		}
+
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		message.EmbedFile(tempFile.Name())
+		embeds := message.GetEmbeds()
+		if len(embeds) != 1 {
+			t.Fatalf("failed to get embeds, expected 1, got: %d", len(embeds))
+		}
+		messageBuf := bytes.NewBuffer(nil)
+		_, err = embeds[0].Writer(messageBuf)
+		if err == nil {
+			t.Error("writer func expected to fail, but didn't")
+		}
+		if !errors.Is(err, os.ErrPermission) {
+			t.Errorf("expected error to be %s, got: %s", os.ErrPermission, err)
+		}
+	})
+	t.Run("EmbedFile with fileFromFS fails on copy", func(t *testing.T) {
+		tempfile, err := os.CreateTemp("testdata/tmp", "embedfile-close-early.*.txt")
+		if err != nil {
+			t.Fatalf("failed to create temp file: %s", err)
+		}
+		t.Cleanup(func() {
+			if err := os.Remove(tempfile.Name()); err != nil {
+				t.Errorf("failed to remove temp file: %s", err)
+			}
+		})
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		message.EmbedFile("testdata/embed.txt")
+		emebeds := message.GetEmbeds()
+		if len(emebeds) != 1 {
+			t.Fatalf("failed to get emebeds, expected 1, got: %d", len(emebeds))
+		}
+		messageBuf, err := os.Open(tempfile.Name())
+		if err != nil {
+			t.Fatalf("failed to open temp file: %s", err)
+		}
+		// We close early to cause an error during io.Copy
+		if err = messageBuf.Close(); err != nil {
+			t.Fatalf("failed to close temp file: %s", err)
+		}
+		_, err = emebeds[0].Writer(messageBuf)
+		if err == nil {
+			t.Error("writer func expected to fail, but didn't")
+		}
+	})
+}
+
+func TestMsg_EmbedReader_unixOnly(t *testing.T) {
+	t.Run("EmbedReader with fileFromReader fails on copy", func(t *testing.T) {
+		tempfile, err := os.CreateTemp("", "embedfile-close-early.*.txt")
+		if err != nil {
+			t.Fatalf("failed to create temp file: %s", err)
+		}
+		t.Cleanup(func() {
+			if err := os.Remove(tempfile.Name()); err != nil {
+				t.Errorf("failed to remove temp file: %s", err)
+			}
+		})
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		file, err := os.Open("testdata/embed.txt")
+		if err != nil {
+			t.Fatalf("failed to open file: %s", err)
+		}
+		t.Cleanup(func() {
+			if err := file.Close(); err != nil {
+				t.Errorf("failed to close file: %s", err)
+			}
+		})
+		if err = message.EmbedReader("embed.txt", file); err != nil {
+			t.Fatalf("failed to embed reader: %s", err)
+		}
+		embeds := message.GetEmbeds()
+		if len(embeds) != 1 {
+			t.Fatalf("failed to get embeds, expected 1, got: %d", len(embeds))
+		}
+		messageBuf, err := os.Open(tempfile.Name())
+		if err != nil {
+			t.Fatalf("failed to open temp file: %s", err)
+		}
+		// We close early to cause an error during io.Copy
+		if err = messageBuf.Close(); err != nil {
+			t.Fatalf("failed to close temp file: %s", err)
+		}
+		_, err = embeds[0].Writer(messageBuf)
+		if err == nil {
+			t.Error("writer func expected to fail, but didn't")
+		}
+	})
+	t.Run("EmbedReader with fileFromReader on closed reader", func(t *testing.T) {
+		tempfile, err := os.CreateTemp("", "embedfile-close-early.*.txt")
+		if err != nil {
+			t.Fatalf("failed to create temp file: %s", err)
+		}
+		if err = tempfile.Close(); err != nil {
+			t.Fatalf("failed to close temp file: %s", err)
+		}
+		t.Cleanup(func() {
+			if err := os.Remove(tempfile.Name()); err != nil {
+				t.Errorf("failed to remove temp file: %s", err)
+			}
+		})
+		message := NewMsg()
+		if message == nil {
+			t.Fatal("message is nil")
+		}
+		if err = message.EmbedReader("embed.txt", tempfile); err == nil {
+			t.Fatalf("expected error, got nil")
+		}
+	})
+}
+
 // TestMsg_WriteToSendmailWithContext tests the WriteToSendmailWithContext() method of the Msg
 func TestMsg_WriteToSendmailWithContext(t *testing.T) {
 	if os.Getenv("TEST_SENDMAIL") != "true" {