fix: make RSVP email sending optional; skip if EMAIL_USER is not set

backend/src/index.ts

@@ -300,7 +300,9 @@ app.post('/api/events/:slug/rsvp', async (req: Request, res: Response) => {
     const eventTitle = eventInfo ? eventInfo.title : slug;
     const eventSlug = eventInfo ? eventInfo.slug : slug;
 
-    // Send RSVP confirmation email to admin
+    // Optionally send RSVP confirmation email to admin if EMAIL_USER is set
+    const adminEmail = process.env.EMAIL_USER;
+    if (adminEmail) {
       try {
         await sendRSVPEmail({
           eventTitle,
@@ -312,11 +314,12 @@ app.post('/api/events/:slug/rsvp', async (req: Request, res: Response) => {
           guestNames: parsedGuestNames,
           itemsBringing: parsedItemsBringing,
           otherItems: other_items || '',
-        to: process.env.EMAIL_USER,
+          to: adminEmail,
         });
       } catch (emailErr) {
         console.error('Error sending RSVP email:', emailErr);
       }
+    }
 
     // Return the complete RSVP data including the parsed arrays
     res.status(201).json({