A transmittal letter is a short letter that accompanies a document or package being sent to someone. It briefly explains what is being sent and why it is being sent. Full definition
Aside from transmittal letters, we also have Transfer Letter Templates and Promotion Letter Templates which you may both use as references for specific purposes that they can help you with. (template.net)
A cover letter for Marketing Analyst resume should serve as an eye catching professional transmittal letter for your resume. (coverlettersandresume.com)
Vermont State Auditor - Cannabis Eradication Report Transmittal Letter, Executive Summary, and Final Report, available in HTML and MS Word formats. (industrialhemp.net)