JeguePanel is a panel to provide easy management of GNU/Linux servers. It makes services configuration (email and samba) much more easy and efficient, and handles user and permissions management. It's integrated with monitoring tools and a lot of control programs like anti-virus, anti-spam, reports, etc. It has English, Portuguese, and Spanish translations. It can use OpenLDAP, PostgreSQL, or MySQL as a backend, and has full integration with Active Directory. It will show different interfaces to users based on permission levels.
saop adds authentication to any SMTP server by using a POP3 or IMAP4 server as the authentication backend. To do so, it sits in the middle of an SMTP session and intercepts login attempts. It then captures the user and password and authenticates against a POP3 server, an IMAP4 server, or a password list.
AfterLogic XMail Server is an email server. It supports ESMTP, TLS/SSL secure connections, SMTP authentication, account and domain aliasing, anti-spam features (IP-based and email address based), mailing lists, logging, remote administration, the Finger protocol, filters, and custom mail processing. AfterLogic XMail Server is based on the XMail server, but features simultaneous multi-user access to a POP3 mailbox, the ability to configure port numbers via a configuration file, a Windows installer, and a Web administration tool with an AJAX interface.