The Real Housewives of New York's Ramona Singer is dealing with yet another war of words with her husband's mistress. Despite sending Kasey Dexter a cease and desist letter, the personal trainer and fitness buff is fighting back, claiming that both Ramona and her husband Mario have been sending her "thousands of emails and texts as well as phone calls."'

Real Housewives Of New York: Is Ramona Singer's Husband Still Cheating On Her With His Mistress?

In an email that Kasey sent to the Singer's lawyers, she says that the couple have been harassing her and that she has no intentions of continuing any sort of relationship with Mario, despite their cheating scandal.

In the email, Kasey even claims that Mario told her he was calling it quits with Ramona by putting an end to their marriage. "As of last Thursday, [Mario] informed me he was leaving Ramona. So I hope [you] can understand the anguish he has put me through. He's lucky I did not get an order of protection against him!"

Ramona earlier sent a cease and desist letter, alleging that Kasey has been harassing them with "unsolicited, lewd, lascivious and salacious messages" despite their repeated requests for Kasey to leave them alone.

Despite the letter, an inside source says that Mario is still reaching out to Kasey.

Is Ramona Singer Patching Things Up In Her Marriage To Help Save Her Image?

"That letter won't hold up in court," the insider tells Life & Style Magazine.  "Mario has been calling Kasey and crying. He wants Kasey in his life."

Ramona seperated from Mario following his cheating scandal but has since then reconciled with her husband.