MIX (Email)

MIX is a high-performance, indexed, on-disk email storage system that is designed for use with the IMAP protocol. MIX was designed by Mark Crispin, the author of the IMAP protocol. Server support for it has been included in releases of UW IMAP since 2006, Panda IMAP, and Messaging Architects Netmail. MIX is also supported directly by the Alpine e-mail client.