Patnorsoft
- Email sending, receiving, retrieving via SMTP and validation.
- http://www.patnorsoft.com/

4ASPNET POP3 .Net Component
- Secure authentication (APOP) support; ability to retrieve headers only; retrieve file, HTML and text attachments; delete messages; custom headers support; content type, content transfer encoding, and charset support.
- http://www.4-asp.net/products/pop3.aspx

EmailQ.NET
- E-mail queuing component for .NET. By ExclamationSoft Inc.
- http://www.exclamationsoft.com/exclamationsoft/emailq.net/

EasyMail .Net Edition
- Compose, send, retrieve and parse Internet Email messages. Includes assemblies for SMTP, POP3 and IMAP4. By Quicksoft Corp.
- http://www.quiksoftcorp.com/emdotnet/

devMail.Net
- SMTP and POP3 assemblies for integrating email capabilities into your applications. By devBiz Business Solutions.
- http://www.devmail.net/

ExclamationSoft SMTP.NET
- Email component with features beyond that of the built-in .NET libraries.
- http://www.exclamationsoft.com/exclamationsoft/smtp.net/

Chilkat EMAIL.NET
- Send, receive and manage email. Full S/MIME capability and MHTML support.
- http://www.chilkatsoft.com/dotNetEmail.asp

aspNetPOP3
- Download email from POP3 servers. Handles all character sets, authentication, decoding and email parsing. By Advanced Intellect.
- http://www.aspnetpop3.com/

Email Checker .NET
- Check email address syntax and validate against the domain's mail server. By ComponentSpace.
- http://www.componentspace.com/emailchecker.aspx

aspNetEmail
- Sends emails that include authentication, multi-part mime, web pages and datagrids. By Advanced Intellect.
- http://www.aspnetemail.com/

Active Mail
- Collection of components for SMTP, IMAP4, POP3 and NNTP to send templated and databound emails, or receive and parse messages. By Active Up.
- http://www.activeup.com/products/components/activemail/