Simple English definitions for legal terms
Read a random definition: C.O.D.
A transmittal letter is a letter that goes with something that is being delivered. It's like a note that says "here's what I'm giving you." The thing being delivered could be a piece of paper or something bigger like a package.
A transmittal letter is a document that is sent along with another object to serve as a record of that object being delivered. The object being delivered can be a paper document, such as a legal pleading or a report, or it can be a physical object, such as goods or equipment.
These examples illustrate how a transmittal letter is used to provide a record of an object being delivered. By sending a transmittal letter, the sender can prove that the object was delivered and received by the intended recipient.