Version: 4.3.5.0
Send, receive, edit, sign/verify and encrypt/decrypt email messages in any .NET application or service. 

Manage email using standards-based protocols


SMTP, POP3, IMAP4 components interact with servers

  • Integrates .NET features, including generics, IPv6, dual-stack sockets and X509 certificates
  • Secure: Link-level encryption (SSL 2.0, SSL 3.0, PCT, TLS 1.0, 1.1, 1.2) is controlled using simple session properties
  • Progress events report message upload/download activity
  • Log events report data for debugging and display purposes
  • Send any custom command using the exposed TCP connection


SMTP is for sending email

  • Secure
    • Authentication support: CRAM-MD5, GSSAPI and NTLM (with single-sign-on), LOGIN, PLAIN
    • Encrypt and/or sign outbound S/MIME messages
  • Messages can be sent via relay servers, intermediate mail servers, or directly to recipients' domain mail servers
  • Send simple email with a single line of code, or build a complex MailMessage and send it
  • Delivery Status Notification (DSN) fully supported
  • Fast
    • On-the-fly message encoding eliminates intermediate files and delays by streaming encoded message data from the source MailMessage to the destination server
    • Supports pipelining of commands without waiting for server acknowlegements

POP3 is for downloading email

  • Secure
    • Authentication support: CRAM-MD5, GSSAPI and NTLM (with single-sign-on), LOGIN, PLAIN, clear-text, APOP
    • Decrypt and/or verify signed S/MIME messages
  • Easy message management - default behavior populates message size and id without downloading message content
  • Dynamic message retrieval - populate selected messages with just the header, header plus a little content, or the entire message
  • Fast on-the-fly message decoding eliminates intermediate files and delays by streaming encoded message data from the source server to the destination MailMessage

IMAP4 downloads mail too, and adds remote mail management

  • Secure
    • Authentication support: CRAM-MD5, GSSAPI and NTLM (with single-sign-on), LOGIN, PLAIN, clear-text
    • Decrypt and/or verify signed S/MIME messages
  • Rich and capable object model
    • IMAP4 commands synchronize the local object model with the server (change the local model and the server is changed)
    • ImapMessage class represents a message in a mailbox - use to change server-side message flags and get a single message
    • Mailbox class represents a server-side mailbox that contains messages - use to alter mailbox properties, enumerate messages, get messages in bulk and append new messages
    • MailboxCollection class represents child mailboxes -  use to manage nested mailboxes
    • Update event informs client of dynamic updates to the selected mailbox
    • Retrieve an entire message, headers only, attachments only, or any part desired
  • Fast on-the-fly message decoding eliminates intermediate files and delays by streaming encoded message data from the source server to the destination MailMessage

MailMessage class at the core of the system

  • Represents a decoded MIME, Secure MIME (S/MIME), or non-MIME (straight ASCII) Internet email message
  • Dynamic encoding occurs when the encoding stream is read from; dynamic decoding occurs when encoding stream is written to
  • Can be used independent of protocol components as a general-purpose MIME or S/MIME encoder/decoder
  • Rich object model represents each header, text, html, attachment, part, and resource element
  • Attachments are decoded and stored in temp files by default, but can optionally be stored in MemoryStreams if disk access is not desired