fix(email): detect and surface webhook send failures instead of claiming success

send_webhook_email() only returned False on a network exception — a
webhook that responded with a non-2xx status (bad URL, wrong API key,
misconfigured Power Automate flow) was still reported as delivered. Now
checks response.ok and returns False on rejection too.

send_password_setup_email() also never checked the return value at all,
so the admin's 'Send Email' action (including resending a password-reset
email after the user already set their password) always showed success
even when nothing was actually sent. Now raises a clear error instead.

backend/app/services/password_setup_service.py

@@ -65,7 +65,11 @@ def send_password_setup_email(db: Session, user: User) -> None:
         f"{set_password_url}\n\n"
         "This link expires in 24 hours and can only be used once."
     )
-    send_webhook_email(db, to=user.email, subject=subject, message=message, full_name=user.full_name)
+    sent = send_webhook_email(db, to=user.email, subject=subject, message=message, full_name=user.full_name)
+    if not sent:
+        raise BusinessRuleViolation(
+            "Failed to send the email — check the webhook URL/API key in Settings and the server logs."
+        )
 
 
 def _get_valid_token_or_raise(db: Session, token: str) -> PasswordSetupToken:

backend/app/services/webhook_email_service.py

@@ -159,8 +159,9 @@ def send_webhook_email(
     """POST a notification email to the configured webhook.
 
     Best-effort: returns False (and logs a warning) if no webhook is
-    configured, *to* is empty, or the request fails — never raises, since
-    a webhook outage must not break whatever triggered the notification.
+    configured, *to* is empty, the request fails, or the webhook responds
+    with a non-2xx status — never raises, since a webhook outage must not
+    break whatever triggered the notification.
     """
     if not to:
         return False
@@ -174,12 +175,18 @@ def send_webhook_email(
     headers = {"x-api-key": api_key} if api_key else {}
 
     try:
-        requests.post(
+        response = requests.post(
             webhook_url,
             json={"to": to, "subject": subject, "body": build_email_body(full_name, message)},
             headers=headers,
             timeout=10,
         )
+        if not response.ok:
+            logger.warning(
+                "Email webhook rejected the request for %s: HTTP %d — %s",
+                to, response.status_code, response.text[:500],
+            )
+            return False
         return True
     except requests.RequestException:
         logger.warning("Email webhook call failed for %s", to, exc_info=True)