This is a third party debt collector illegally posing as a representative of law enforcement or the local courts.  Using cleverly cadenced "legalese" and intimidating buzz words such as "claims against you" and "charges outstanding" and "you have been notified" and "please be advised" they attempt to illicit a call to the "agency handling the case" by giving the "respondent" one last chance for absolution by contacting the "agency" to avoid "further action" on the case.