IMAP Proxy

IMAP Proxy is a fantastic program that serves as a caching IMAP proxy server. This software came into existence as a response to the issue of webmail clients, which failed to maintain persistent connections to an IMAP server. The reason being, most webmail clients had to keep logging in to an IMAP server time and time again for every single transaction, which eventually slowed down the system's performance.

IMAP Proxy comes as a solution to this issue by keeping the server connections open for a short time after the webmail client logs out, and when the client tries connecting again, it checks to see if there's a cached connection available and reuses the same if possible. The program keeps track of user connections to the server via a little record containing the username, an md5 digital signature of the password, and the server socket descriptor being used, which is filled upon successful login.

The records are stored in a hash table in memory, and IMAP Proxy can support multiple backend servers through running multiple instances of the software and ensuring each instance uses a different configuration file. In summary, IMAP Proxy is an excellent caching IMAP proxy server, offering stability to webmail clients that are unable to maintain persistent connections to an IMAP server.