1)   Winmail Mail Server 4.3
Winmail Server is an enterprise class mail server software system offering a robust feature set, including extensive security measures. Winmail Server supports SMTP, POP3, IMAP, Webmail, LDAP, multiple domains, SMTP authentication, spam protection

 2)   MailBee SMTP 5.4
MailBee SMTP is a powerful and easy to use COM object which enables ASP and Windows applications to create, send and queue mail to SMTP servers. Secure authentication, email validation, correct MIME composer, multiple attachments, SMIME, and more.

 3)   Arclab Email Toolbox 2.0
Incorporate email send (SMTP/ESMTP/Direct Relay) into your application or script. Arclab Email Toolbox is a COM-based component for use with Visual Basic, Visual C++, Access, Excel, ASP, VBscript and other COM compatible containers.

 4)   ANSMTP SMTP Component Build 7.1
Powerful, easy- to-use and full-featured SMTP email component enables your ASP, VB, VBA, VC++, C#, VB.NET, JScript.NET, ASP.NET or other COM environment applications to send rich TEXT/HTML email based on SMTP/ESMTP protocol. Support IPv6.

 5)   EASendMail SMTP Component (.NET Edition) 2.0
Powerful, easy- to-use and full-featured SMTP email component enables your C#, VB.NET, JScript.NET, ASP.NET or other .NET framework applications to send rich TEXT/HTML email based on SMTP/ESMTP protocol. Featured examples are included.

 6)   EAGetMail POP3 & IMAP4 Component (.NET Edition) 1.0
EAGetMail enables your C#, VB.NET, JScript.NET, ASP.NET or other .NET framework applications to parse and receive email based on POP3/IMAP4 protocol. Many advanced features are supported including TNEF parser (winmail.dat) and S/MIME.