An e-mail attachment (or email attachment) is a computer file which is sent along with an e-mail message. The file may be sent as a separate message, but now it is almost universally sent as part of the message to which it is attache. Attached messages may be sent in unencoded form, or encoded in a number of ways: base64, binhex, uuencoding, quoted-printable. In MIME, the standard Internet e-mail format, messages and their attachments are sent as a single multipart message, usually using base64 encoding for non-text attachments.