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[bleckfala]

Pues nose pk utilisas las ' ' si no son necesarias mucho menos en el nombre de la tabla

$sqlex="SELECT 'email', COUNT(*) AS 'total', SUM('monto') AS 'suma' FROM 'factura' GROUP BY 'email'";

prueba asi

$sqlex="SELECT email, COUNT(*) AS total, SUM(monto) AS suma FROM factura GROUP BY email";