If you decide to do it alone, your letter should state the specific defamatory statements made, confirm that they are defamatory, indicate the reputational harm caused, demand an apology and retraction of those statements, and demand that they cease making further statements failing which you will sue them.
THEREFORE, you are hereby requested to immediately cease and desist illegal defamation, slander and/or libel and within 10 business days, return the signed written assurance below affirming that you will refrain from any further acts of defamation, slander and/or libel with regards to my character and/or reputation.
Whoever, by words either spoken or intended to be read, or by signs or by visible representations, makes or publishes in any manner, any imputation concerning any person intending to harm, or knowing or having reason to believe that such imputation will harm, the reputation of such person, is said, except in the cases ...
An effective defamation cease and desist letter will usually begin with a clear and factual introduction of the involved parties. Following this, the letter should present the facts in a chronological order, beginning with the earliest incident and progressing through subsequent events.
A defamatory statement must be an assertion of fact, not an opinion. For example, if your boss says that you are not a very nice person, then that statement is likely to be an opinion. On the other hand, if your boss says you have been stealing from the company, that is a statement of fact, not opinion.
If you decide to do it alone, your letter should state the specific defamatory statements made, confirm that they are defamatory, indicate the reputational harm caused, demand an apology and retraction of those statements, and demand that they cease making further statements failing which you will sue them.
I am writing because you recently made defamatory statements about me my company my company and me. I ask that you immediately retract these statements. On date, you summarize what recipient did that is defamatory.
Your letter should ideally state the specific defamatory statement, the reasons why it is untrue, and the damage you're suffering. Also, give the recipient a deadline by which they must retract their statements before you will need to take legal action.
However, sending a letter of demand can have its disadvantages. Depending on the situation, the other party may feel threatened and respond negatively, or they may not respond at all. They might engage a lawyer, or they might even start legal action against you.
The label "in care of" simply means you are sending the letter or package to an addressee that is accepting the correspondence for the intended recipient. People often use the abbreviation "c/o" to send mail to someone they don't have an address for or to send mail to themselves at someone else's residence.