From 0b622368baa7c73731529e38ff0a5475a7a4328c Mon Sep 17 00:00:00 2001
From: Winni Neessen <wn@neessen.net>
Date: Tue, 23 Jan 2024 11:01:08 +0100
Subject: [PATCH 1/2] #166: Add delivery status indication for messages

This update introduces a new property, `isDelivered`, in the message struct to track if a message has been successfully sent or not. Additionally, this also includes a new helper function `IsDelivered` to easily retrieve the status. This feature enhances the tracking capabilities of outgoing messages across different client files.
---
 client_119.go | 1 +
 client_120.go | 1 +
 msg.go        | 8 ++++++++
 3 files changed, 10 insertions(+)

diff --git a/client_119.go b/client_119.go
index 3165a2d6..df09e18b 100644
--- a/client_119.go
+++ b/client_119.go
@@ -91,6 +91,7 @@ func (c *Client) Send(ml ...*Msg) error {
 			errs = append(errs, se)
 			continue
 		}
+		m.isDelivered = true
 
 		if err := w.Close(); err != nil {
 			se := &SendError{Reason: ErrSMTPDataClose, errlist: []error{err}, isTemp: isTempError(err)}
diff --git a/client_120.go b/client_120.go
index 69eb5b33..1c0a5be5 100644
--- a/client_120.go
+++ b/client_120.go
@@ -88,6 +88,7 @@ func (c *Client) Send(ml ...*Msg) (rerr error) {
 			rerr = errors.Join(rerr, m.sendError)
 			continue
 		}
+		m.isDelivered = true
 
 		if err := w.Close(); err != nil {
 			m.sendError = &SendError{Reason: ErrSMTPDataClose, errlist: []error{err}, isTemp: isTempError(err)}
diff --git a/msg.go b/msg.go
index a3ce3dab..c97fc01b 100644
--- a/msg.go
+++ b/msg.go
@@ -94,6 +94,9 @@ type Msg struct {
 	// genHeader is a slice of strings that the different generic mail Header fields
 	genHeader map[Header][]string
 
+	// isDelivered signals if a message has been delivered or not
+	isDelivered bool
+
 	// middlewares is the list of middlewares to apply to the Msg before sending in FIFO order
 	middlewares []Middleware
 
@@ -507,6 +510,11 @@ func (m *Msg) SetUserAgent(a string) {
 	m.SetGenHeader(HeaderXMailer, a)
 }
 
+// IsDelivered will return true if the Msg has been successfully delivered
+func (m *Msg) IsDelivered() bool {
+	return m.isDelivered
+}
+
 // RequestMDNTo adds the Disposition-Notification-To header to request a MDN from the receiving end
 // as described in RFC8098. It allows to provide a list recipient addresses.
 // Address validation is performed

From 6746af4605b6a32b8daa92ff1505415b802b6203 Mon Sep 17 00:00:00 2001
From: Winni Neessen <wn@neessen.net>
Date: Tue, 23 Jan 2024 11:21:56 +0100
Subject: [PATCH 2/2] Update client tests for message delivery indication

This commit adds checks in the testing functions to verify the successful implementation of message delivery status. A new attribute `isDelivered` is now being validated in our tests, reinforcing the message tracking system and enhancing the overall reliability of our application.
---
 client_test.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/client_test.go b/client_test.go
index afc5743a..8c35e192 100644
--- a/client_test.go
+++ b/client_test.go
@@ -763,6 +763,9 @@ func TestClient_DialSendClose(t *testing.T) {
 	if err := c.Close(); err != nil {
 		t.Errorf("Close() failed: %s", err)
 	}
+	if !m.IsDelivered() {
+		t.Errorf("message should be delivered but is indicated no to")
+	}
 }
 
 // TestClient_DialAndSendWithContext tests the DialAndSendWithContext() method of Client
@@ -1134,7 +1137,9 @@ func TestClient_DialAndSendWithContext_withSendError(t *testing.T) {
 	}
 	if se.IsTemp() {
 		t.Errorf("expected permanent error but IsTemp() returned true")
-		return
+	}
+	if m.IsDelivered() {
+		t.Errorf("message is indicated to be delivered but shouldn't")
 	}
 }