Does the letter itself prohibit sales?
A private demand is not a court injunction. Section 271(a) defines specified acts of infringement during a patent's term, while section 283 authorizes courts to grant injunctions under equitable principles. Obtain any order the sender references and read its actual terms.
Does continued selling automatically mean treble damages?
No. Eko Brands, LLC v. Adrian Rivera Maynez Enterprises, Inc. distinguishes the factfinder's willfulness inquiry into deliberate or intentional infringement from the court's later enhancement decision. Under Halo Electronics, Inc. v. Pulse Electronics, Inc., enhanced damages are discretionary and directed at egregious misconduct. Notice and subsequent conduct can matter, but receipt of a letter does not establish the necessary findings.
What should the review produce?
Identify the asserted claims, relevant product versions, possible defenses, and any available redesign or license. Estimate exposure for past and future activity separately. Document the actual investigation and preserve relevant records; an unsupported assurance from a sales team is not a technical analysis.