Which binary coding is most often used for email?

• A. SMTP
• B. Uuencode
• C. IMAP
• D. MIME

Answer: (D)

Binary data can’t travel through a plain text email, so emails use a standard way to encode attachments and multimedia. MIME defines how to encode binary content into ASCII text (for example, using base64) and how to structure messages with multiple parts and different content types. This makes attachments and diverse data safely transmittable over the email system and interoperable across servers and clients. SMTP is the transport protocol, IMAP is a mailbox access protocol, and Uuencode was an older method before MIME became the standard; MIME essentially handles the encoding and structure needed for binary data in modern email.