Virtual Qmail - virtual domains management system for qmail. It is designed to be fast, reliable, and easy to use. Includes software allowing users to manage their accounts via WWW.
Ni!Mail is a webmail connecting to an IMAP server and using python/nevow/twisted to provide a clean and fast interface. It uses nevow livepage, a library that uses XMLHTTPRequest, to make it very dynamic.
Active Spam Killer for Windows (AfW) is a challenge/response spam filtering system for the Windows platform. Based on ASK for Linux by Marco Paganini, this project adds a POP3 client/server wrapper and web administration, as well as Windows compatibility
Auth0 Token Vault handles secure token storage, exchange, and refresh for external providers so you don't have to build it yourself.
Rolling your own OAuth token storage can be a security liability. Token Vault securely stores access and refresh tokens from federated providers and handles exchange and renewal automatically. Connected accounts, refresh exchange, and privileged worker flows included.