smime

A cross-platform .NET library for IMAP, POP3, and SMTP.

A .NET MIME creation and parser library with support for S/MIME, PGP, DKIM, TNEF and Unix mbox spools.

Simple API, Complex Emails (Jakarta Mail smtp wrapper)

An S/MIME signing utility for use with Git

[DEPRECATED — See notice in README.md and switch to OpenSSL 3 OQS Provider] Fork of OpenSSL 1.1.1 that includes prototype quantum-resistant algorithms and ciphersuites based on liboqs

en-crypt, de-crypt, si-gn, ve-rify - smime, pdf, xades and plain files in pure python

ACME (RFC 8555) compatible implementation, connecting to Active Directory Certificate Services (ADCS)

ACME Email Client for EmailReply-00 Challenge

A C/C++ MIME creation and parser library with support for S/MIME, PGP, and Unix mbox spools.

.NET email library and proxy supporting IMAP, POP3, and SMTP with S/MIME and PGP.

cryptlib security toolkit

AS2 Library for building and parsing Messages and MDNs

API specification for gematik's KIM - a secure Email standard, which enables the exchange of information and payload in the German healthcare sector.

🔐 📧 Encrypts WordPress emails using OpenPGP or S/MIME with a familiar API.

A S/MIME library for JavaMail

A toolkit for generating self-signed digital certificates for signing PDFs, emails, software, and other content using tools like JSignPdf or any software that supports PKCS#12.

View and compose SMIME encrypted messages in Outlook Web App on Linux

Self-hosted web PKI for the full X.509 & SSH certificate lifecycle — private keys in Cosmian KMS, with a Kubernetes cert-manager external issuer and CRL/KRL revocation.

S/MIME encoder in pure python

Aegis Implicit Mail