Abstract: An electronic mail system with a methodology providing distributed message storage and processing is described. In particular, this methodology breaks up how the individual components of message data are stored. Message data itself is broken up into two parts: a metadata (mutable) portion, and an immutable portion. The metadata portion represents that part of the message data that may change over time. This includes message status flags (e.g., the IMAP “message deleted” flag) and the message's position within a particular message folder, among other information. The immutable portion, which comprises the bulk of electronic mail data (namely, the message itself), once stored is never edited. Immutable data is written f+1 times on as many unique servers, to tolerate f number of server failures using Lampson's stable storage algorithm. The metadata portion is stored 2f+1 times on as many unique servers to tolerate f number of server failures using quorum voting.

Abstract: An electronic mail system with a methodology providing distributed message storage and processing is described. In particular, this methodology breaks up how the individual components of message data are stored. Message data itself is broken up into two parts: a metadata (mutable) portion, and an immutable portion. The metadata portion represents that part of the message data that may change over time. This includes message status flags (e.g., the IMAP “message deleted” flag) and the message's position within a particular message folder, among other information. The immutable portion, which comprises the bulk of electronic mail data (namely, the message itself), once stored is never edited. Immutable data is written f+1 times on as many unique servers, to tolerate f number of server failures using Lampson's stable storage algorithm. The metadata portion is stored 2f+1 times on as many unique servers to tolerate f number of server failures using quorum voting.