Mark Crispin, American computer scientist, designed the IMAP (died 2012)

Mark Reed Crispin is best known as the father of the Internet Message Access Protocol (IMAP), having invented it in 1985 during his time at the Stanford Knowledge Systems Laboratory. He is the author or co-author of numerous RFCs and was the principal author of UW IMAP, one of the reference implementations of the IMAP4rev1 protocol described in RFC 3501. He also designed the MIX mail storage format.

In computing, the Internet Message Access Protocol (IMAP) is an Internet standard protocol used by email clients to retrieve email messages from a mail server over a TCP/IP connection. IMAP is defined by RFC 9051.