/ ətætʃmənt /
A file that accompanies an e-mail message. As transmitted, an attached file is an exact copy of the original file located on the sender’s computer. The file can be a document, an executable program, or a compressed file containing more than one item, among other types of files. The file is not part of the actual e-mail message, and it is generally encoded using uuencoding, MIME, or BinHex. Most e-mail programs automatically encode an attached document for transmission with a message. The recipient of the message must have an e-mail program capable of decoding the attached document or use a separate utility to decode it in order to read the document. Some gateways prohibit transmission of files over a certain size. Most e-mail systems permit more than one file to be attached to an e-mail message at a time.