getmail is intended as a simple, secure, and reliable replacement for fetchmail. It retrieves email (either all messages, or only unread messages) from one or more POP3, SPDS, or IMAP4 servers (with or without SSL) for one or more email accounts, and reliably delivers into qmail-style Maildirs, mboxrd files, or through external MDAs (command deliveries) specified on a per-account basis. getmail also has excellent support for domain (multidrop) mailboxes, including delivering messages to different users or destinations based on the envelope recipient address.
SendEmail is a lightweight, completely command line-based SMTP email delivery program. If you have the need to send email from a command prompt this tool is perfect. It was designed to be used in bash scripts, Perl programs, and Web sites, but it is also quite useful in many other contexts. It is written in Perl, and is unique in that it requires no special modules, and supports any platform that runs Perl. It has a straightforward interface, making it very easy to use.
E-MailRelay is a simple SMTP store-and-forward mail transport agent (MTA). It runs as an SMTP server, storing incoming e-mail in a local spool directory, and then forwarding the stored messages to a downstream SMTP server on request. It can also run as a proxy server, forwarding (and optionally pre-processing) incoming e-mail as soon as it is received. It does not do any message routing other than to a local postmaster. Because of its simplicity E-MailRelay is extremely easy to configure, typically requiring only the address of the downstream SMTP server to be put on the commandline.
CsvMail is an HTML form mailer and manager. It mails the results of form submissions and also writes the entry to a secure.csv file. It requires minimal HTML form changes - just change the beginning form tag to post to CsvMail. It is very easy to configure, but includes plenty of extra options, including domain security settings and a bounceback required fields option. A fully-functional evaluation version is available.
XMail Queue Manager gives you control over an XMail Server's multi-level nested mail queue. You can use it to track messages in their different states (sending, resending, and frozen). Statistics tell you about the number of spooled messages. You can sort entries by any column header field, and can start and stop the server directly. The cross platform remote control feature allows you to manage queues on remote servers without a GUI.
YahooPOPs! is an application which emulates a POP3 mail server and provides free POP3 access to Yahoo! It does not depend on Yahoo's POP3 mail server. You can use a POP3 mail client of your choice. This application emulates a POP3 server and enables popular email clients like Outlook, Netscape, Eudora, Mozilla, and Calypso to download email from Yahoo! accounts.
Chandler is a standards-based "Note-to-Self Organizer" designed for personal and small-group task management and calendaring. It consists of a desktop application and Chandler Hub, a free sharing service and Web application. You can also download and run your own Chandler Server.