diff --git a/coderd/notifications/dispatch/webhook.go b/coderd/notifications/dispatch/webhook.go
index c1fb47ea35692..4a548b40e4c2f 100644
--- a/coderd/notifications/dispatch/webhook.go
+++ b/coderd/notifications/dispatch/webhook.go
@@ -78,11 +78,16 @@ func (w *WebhookHandler) dispatch(msgPayload types.MessagePayload, title, body,
 			return false, xerrors.Errorf("create HTTP request: %v", err)
 		}
 		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("X-Message-Id", msgID.String())
 
 		// Send request.
 		resp, err := w.cl.Do(req)
 		if err != nil {
-			return true, xerrors.Errorf("failed to send HTTP request: %v", err)
+			if errors.Is(err, context.DeadlineExceeded) {
+				return true, xerrors.Errorf("request timeout: %w", err)
+			}
+
+			return true, xerrors.Errorf("request failed: %w", err)
 		}
 		defer resp.Body.Close()
 
@@ -93,11 +98,11 @@ func (w *WebhookHandler) dispatch(msgPayload types.MessagePayload, title, body,
 			lr := io.LimitReader(resp.Body, int64(len(respBody)))
 			n, err := lr.Read(respBody)
 			if err != nil && !errors.Is(err, io.EOF) {
-				return true, xerrors.Errorf("non-200 response (%d), read body: %w", resp.StatusCode, err)
+				return true, xerrors.Errorf("non-2xx response (%d), read body: %w", resp.StatusCode, err)
 			}
 			w.log.Warn(ctx, "unsuccessful delivery", slog.F("status_code", resp.StatusCode),
 				slog.F("response", respBody[:n]), slog.F("msg_id", msgID))
-			return true, xerrors.Errorf("non-200 response (%d)", resp.StatusCode)
+			return true, xerrors.Errorf("non-2xx response (%d)", resp.StatusCode)
 		}
 
 		return false, nil
diff --git a/coderd/notifications/dispatch/webhook_test.go b/coderd/notifications/dispatch/webhook_test.go
new file mode 100644
index 0000000000000..546fbc2e88057
--- /dev/null
+++ b/coderd/notifications/dispatch/webhook_test.go
@@ -0,0 +1,145 @@
+package dispatch_test
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"cdr.dev/slog"
+	"cdr.dev/slog/sloggers/slogtest"
+	"github.com/coder/serpent"
+
+	"github.com/coder/coder/v2/coderd/notifications/dispatch"
+	"github.com/coder/coder/v2/coderd/notifications/types"
+	"github.com/coder/coder/v2/codersdk"
+	"github.com/coder/coder/v2/testutil"
+)
+
+func TestWebhook(t *testing.T) {
+	t.Parallel()
+
+	const (
+		titleTemplate = "this is the title ({{.Labels.foo}})"
+		bodyTemplate  = "this is the body ({{.Labels.baz}})"
+	)
+
+	msgPayload := types.MessagePayload{
+		Version:          "1.0",
+		NotificationName: "test",
+		Labels: map[string]string{
+			"foo": "bar",
+			"baz": "quux",
+		},
+	}
+
+	tests := []struct {
+		name          string
+		serverURL     string
+		serverTimeout time.Duration
+		serverFn      func(uuid.UUID, http.ResponseWriter, *http.Request)
+
+		expectSuccess   bool
+		expectRetryable bool
+		expectErr       string
+	}{
+		{
+			name: "successful",
+			serverFn: func(msgID uuid.UUID, w http.ResponseWriter, r *http.Request) {
+				var payload dispatch.WebhookPayload
+				err := json.NewDecoder(r.Body).Decode(&payload)
+				assert.NoError(t, err)
+				assert.Equal(t, "application/json", r.Header.Get("Content-Type"))
+				assert.Equal(t, msgID, payload.MsgID)
+				assert.Equal(t, msgID.String(), r.Header.Get("X-Message-Id"))
+
+				w.WriteHeader(http.StatusOK)
+				_, err = w.Write([]byte(fmt.Sprintf("received %s", payload.MsgID)))
+				assert.NoError(t, err)
+			},
+			expectSuccess: true,
+		},
+		{
+			name: "invalid endpoint",
+			// Build a deliberately invalid URL to fail validation.
+			serverURL:       "invalid .com",
+			expectSuccess:   false,
+			expectErr:       "invalid URL escape",
+			expectRetryable: false,
+		},
+		{
+			name:            "timeout",
+			serverTimeout:   time.Nanosecond,
+			expectSuccess:   false,
+			expectRetryable: true,
+			expectErr:       "request timeout",
+		},
+		{
+			name: "non-200 response",
+			serverFn: func(_ uuid.UUID, w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(http.StatusInternalServerError)
+			},
+			expectSuccess:   false,
+			expectRetryable: true,
+			expectErr:       "non-2xx response (500)",
+		},
+	}
+
+	logger := slogtest.Make(t, &slogtest.Options{IgnoreErrors: true}).Leveled(slog.LevelDebug)
+
+	// nolint:paralleltest // Irrelevant as of Go v1.22
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			timeout := testutil.WaitLong
+			if tc.serverTimeout > 0 {
+				timeout = tc.serverTimeout
+			}
+
+			var (
+				err   error
+				ctx   = testutil.Context(t, timeout)
+				msgID = uuid.New()
+			)
+
+			var endpoint *url.URL
+			if tc.serverURL != "" {
+				endpoint = &url.URL{Host: tc.serverURL}
+			} else {
+				// Mock server to simulate webhook endpoint.
+				server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+					tc.serverFn(msgID, w, r)
+				}))
+				defer server.Close()
+
+				endpoint, err = url.Parse(server.URL)
+				require.NoError(t, err)
+			}
+
+			cfg := codersdk.NotificationsWebhookConfig{
+				Endpoint: *serpent.URLOf(endpoint),
+			}
+			handler := dispatch.NewWebhookHandler(cfg, logger.With(slog.F("test", tc.name)))
+			deliveryFn, err := handler.Dispatcher(msgPayload, titleTemplate, bodyTemplate)
+			require.NoError(t, err)
+
+			retryable, err := deliveryFn(ctx, msgID)
+			if tc.expectSuccess {
+				require.NoError(t, err)
+				require.False(t, retryable)
+				return
+			}
+
+			require.ErrorContains(t, err, tc.expectErr)
+			require.Equal(t, tc.expectRetryable, retryable)
+		})
+	}
+}