fix: add detailed smtp logging to debug confirmation email

app/api/contact/route.ts

@@ -115,16 +115,23 @@ export async function POST(req: Request) {
         }),
       );
 
-      await transporter.sendMail({
-        from: config.mail.from,
-        to,
-        replyTo: email,
-        subject: `Kontaktanfrage von ${name}`,
-        html: notificationHtml,
-      });
+      try {
+        const info = await transporter.sendMail({
+          from: config.mail.from,
+          to,
+          replyTo: email,
+          subject: `Kontaktanfrage von ${name}`,
+          html: notificationHtml,
+        });
+        logger.info("Notification email sent successfully", { messageId: info.messageId });
+      } catch (notifyError) {
+        logger.error("Failed to send notification email", { error: notifyError });
+        throw notifyError; // Re-throw to be caught by the outer SMTP catch
+      }
 
       // 2b. Confirmation to the User
       try {
+        logger.info("Preparing to send confirmation email", { to: email });
         const confirmationHtml = await render(
           React.createElement(ConfirmationMessage, {
             name,
@@ -132,16 +139,17 @@ export async function POST(req: Request) {
           }),
         );
 
-        await transporter.sendMail({
+        const info = await transporter.sendMail({
           from: config.mail.from,
           to: email,
           subject: `Ihre Kontaktanfrage bei ${clientName}`,
           html: confirmationHtml,
         });
+        logger.info("Confirmation email sent successfully", { messageId: info.messageId });
       } catch (confirmError) {
         logger.warn(
           "Failed to send confirmation email, but notification was sent",
-          { error: confirmError },
+          { error: confirmError instanceof Error ? confirmError.message : String(confirmError) },
         );
       }