My ex-husband's soon-to-be ex wife sent horrible character-destroying emails to my client AND she fwd'd them to my 21yr old son.

Not only emails, but text messages also. I've filed the Police Report and HoustonTX Homicide Sgt sent her a certified letter to Cease and Desist... she hasn't rec'd the letter yet.. and She's STILL sending the emails to my client - who now is not returning my phone calls. I've been told the DA won't take any cases involving libel/defamation in emails.. but maybe they will since some of them are text msgs?(and directly tied to a ph #) I have been told repeatedly that nothing can be done until she threatens bodily harm... in the meantime my character and reputation are being destroyed! She also sent derogatory things under the email address associated with my ex's Employer- a Houston TV station. What can be done to stop her?