75 Pa. C.S. § 1551
The department shall promptly mail a notice to each person whose license is suspended as a result of the accumulation of points under section 1539 (relating to suspension of operating privilege on accumulation of points). The notice shall be mailed to the address of record within six months following the conviction of a violation of this title that resulted in the addition of sufficient points to cause the suspension. Failure of the department to mail notice of suspension as required by this section shall prohibit the department from suspending the license of such person. This section shall not apply to any suspension which would have been imposed as the result of points which have been assigned to a person's record after the person has filed an appeal under section 1550 (relating to judicial review) until the appeal has been finally determined and for six months after the department is notified of the determination. This section shall not apply to a suspension imposed as the result of the determination of the appeal, whether it be the reimposition of the suspension originally ordered or the imposition of a different suspension required because the department must recalculate the record due to a court order.
75 Pa.C.S. § 1551