Update common settings for take USE_ASYNC_FOR_EMAIL from environment
The default value is kept to `False` to ensure backward compatibility functionally.
@@ -245,7 +245,7 @@ EXPLARA_API_TOKEN = "shjbalkfbdskjlbdskljbdskaljfb"
QR_CODES_DIR = ROOT_DIR + '/qr_files'
-USE_ASYNC_FOR_EMAIL = False
+USE_ASYNC_FOR_EMAIL = os.environ.get('USE_ASYNC_FOR_EMAIL', False)
USER_SPAM_THRESHOLD = 2
