There are hundreds of thousands of policies written at Lloyd's. Thankfully, fraudulent policies are extremely rare. They do, however, exist - as unscrupulous people attempt to take advantage of the Lloyd's name. In the first instance, you should always contact the firm or individual that sold you the insurance to get information about your policy or make changes to it.
For US Policyholders, the producer as your agent should be able to secure validation for you from the US broker or Lloyd’s coverholder through whom they sourced cover. Where the producer is uncooperative or unavailable you should file a complaint against them with your local state insurance department. Only when such avenues are exhausted should you direct your enquiry to firstname.lastname@example.org. Note that Lloyd’s will not generally assist third parties or their lawyers seeking to identify coverage. Their recourse is to any alleged policyholder via the notice agent in any policy held and/or the producing insurance agent or broker.
If you wish to report suspicious activity appertaining to an insurance policy at Lloyd’s, a summary of the issue should be sent to email@example.com.