Welcome to IPWorks S/MIME, a powerful developer suite for implementing secure Email communications via S/MIME encryption and digital certificates. Encrypt files and emails, as well as sign and verify message signatures using X.509 digital certificates. IPWorks S/MIME includes a generic S/MIME component along with S/MIME enabled versions of the IPWorks POP3, IMAP, SMTP, FileMailer and HTMLMailer components.

Included Libraries

The .NET Edition includes several libraries (.dll files) which are supported in different environments. The following libraries are present in the lib directory after installation:

  • lib\nsoftware.IPWorksSMIME.dll is designed for use in .NET Framework 4.0 and up, .NET Core 3.0 and up, and .NET 5 and up. This is the default library which maintains a familiar API in line with previous versions of the product.

    Support for asynchronous programming patterns (async/await) is exposed in a separate nsoftware.async.IPWorksSMIME namespace. See the Async Functionality page for details.

  • lib\net6.0\nsoftware.IPWorksSMIME.dll is designed for use in .NET 6 and up. The .NET 6 library provides cross-platform support while maintaining the same API as the default library in lib.

  • lib\netstandard2.0\nsoftware.IPWorksSMIME.dll is designed for use in .NET Standard 2.0 and up. The .NET Standard library provides cross-platform support for legacy projects.

  • lib\net20\nsoftware.IPWorksSMIME.dll is designed for use in .NET Framework 2.0 and up. This library targets .NET Framework 2.0 and is maintained for legacy projects.

Included Components

CertMgrThe CertMgr component is used to create, read, and manage certificates.
MIMEThe MIME component allows for the simple encoding and decoding of MIME structures, such as message attachments and file uploads.
SFileMailerThe SFileMailer Component is used to send emails with file attachments.
SHTMLMailerThe SHTMLMailer Component is used to send HTML emails, including embedded images.
SIMAPThe SIMAP Component is used to communicate with IMAP servers using the Internet Message Access Protocol (IMAP).
SMIMEThe S/MIME component implements the S/MIME standard for encryption and decryption with public key cryptography and X.509 digital certificates.
SNNTPThe SNNTP Component is used to read, search, and post articles on Usenet news servers.
SPOPThe SPOP Component is used to easily retrieve electronic mail from internet post office servers (POP).
SSMTPThe SSMTP Component is used to send Internet mail using the SMTP protocol (the Internet mail standard).

Additional Information

You will always find the latest information about IPWorks S/MIME at our web site: We offer free, fully-functional 30-day trials for all of our products, and our technical support staff are happy to answer any questions you may have during your evaluation.

Please direct all technical questions to To help support technicians assist you as quickly as possible, please provide an detailed and accurate description of your problem, the results you expected, and the results that you received while using our product. For questions about licensing and pricing, and all other general inquiries, please contact

Thank You!

Thank you for choosing IPWorks S/MIME for your development needs. We realize that you have a choice among development tools, and that by choosing us you are counting on us to be a key component in your business. We work around the clock to provide you with ongoing enhancements, support, and innovative products; and we will always do our best to exceed your expectations!