Small town slander

What is the name of your state? Texas

My husband and I have a computer store in the town he used to live in with his (literally) crazy ex. When he divorced his previous wife, the store they leased was in her name. She went to the landlord and had the locks changed so that he could not enter, and told lies about him to the landlord. He was then out of a job with no money coming in. The landlord had never met her before but changed the locks and would not let my husband into the store to get the customers machines out and returned to them. In turn, his ex carried the machines around in her car with most of the machines not reaching their owners. Now, two years later, the landlord of this previous store is calling his old customers, telling new people that they should be careful of him and to try to get their money back for their machines from him. She also wants him to pay for the water bills that arrived after she changed the locks. Can she get in trouble for black mailing him for the water bill and since she is spreading the word to be careful about him, and to not go into our store because he works there, can we sue her for loss of business?

"When he divorced his previous wife,"
*** How long ago was this??

"Can she get in trouble for black mailing him for the water bill"
*** No.

"and since she is spreading the word to be careful about him,"
*** No.

"and to not go into our store because he works there"
*** No.

"can we sue her for loss of business?"
*** Probably not. Though HE may have a claim for defamation against her, he would have a very hard time proving that her statements caused the loss and how much loss there is due to the claims.

Simply, the quality of his work and the services to his customers will usually be the 'true' test that his customers are looking for. That plus a little explanation about the 'sour grapes' being spread by his ex should be sufficient to overcome her negative comments.