MailBee S/MIME ActiveX allows your application to process S/MIME e-mails (encrypt, decrypt, verify and sign). Supports file and registry certificate stores, PFX files, digital signatures. MailBee S/MIME can interoperate with other components like MailBee POP3, IMAP4 or SMTP so that you can decrypt and verify incoming e-mails or encrypt and sign outgoing ones.
MailBee.dll is available in 32-bit and 64-bit versions. It's light-weight and has no visual interface (pure COM component). Works in all Windows versions from 2000 to 2012 with most languages which support ActiveX including C++, Delphi, VB, classic ASP. Samples are available for Borland Delphi, Visual Basic 6, classic ASP. Royalty-free distribution.