MailBee.NET Objects
Brings e-mail capabilities to your .NET applications in a few lines of code. You may choose a part of MailBee.NET Objects by protocol (SMTP, POP3, IMAP, SSL, AntiSpam, Outlook) or by task: create and send, receive, parse, manage IMAP, protect, bulk e-mails, make them safe, protect from spam.

AfterLogic WebMail Pro
Webmail front-end for your existing POP3/IMAP mail server. It uses powerful AJAX interface for faster access to your emails. Calendar resolves multiple groupware tasks including sharing and invitations. Available for both major web platforms: ASP.NET (Windows only) and PHP (Linux/Windows).

AfterLogic MailSuite Pro for Linux
This messaging and collaboration solution includes a web-based admin panel, an SMTP/POP3/IMAP server (MTA), anti-spam and anti-virus protection, plus all the features of AfterLogic WebMail Pro, such as AJAX-based webmail, shared calendars, contacts, and more. It ships as a self-contained installation package for a quick and effortless setup, and available as a free trial.