poplimitd is a daemon process that monitors a server maillog file for POP3 or IMAP connections. Using configurable settings it monitors the rate of logins based on the user account and IP address. If it finds excessive usage, it will send a preconfigured email with the users information to that user asking them to stop. On servers that suffer from high POP3/IMAP load, this can dramatically modify user behaviour and limit POP and IMAP connections and load.
MFilter is a replacement for maildrop/procmail and fetchmail/getmail. It is an email retriever that supports Maildir or command delivery and processing. Its secondary goal is to facilitate the life of the network administrator by centralizing the downloading, filtering, and classification of mail in a simple and flexible way. Some of its features include XML file based configuration and logging of each action taken.
Mail ConfiGuru is a standalone cross-platform tool and library that displays the configuration of email clients available to the currently logged-in user. It provides one interface to the settings of all supported email clients, which currently includes Mozilla Thunderbird, Mozilla Mail (SeaMonkey), MS Outlook, MS Outlook Express, KMail, and Ximian Evolution.