Best smime tools

Self-hosted mail with per-user OpenPGP or S/MIME storage encryption

A plugin-based mail client with PGP and S/MIME support

A keyboard-focused Mac mail client with OpenPGP and S/MIME

A mail client with integrated PGP and S/MIME key workflows

Centrally managed S/MIME and PGP with a webmail fallback

GNOME mail with documented GPG and S/MIME workflows

Policy-driven encryption with several recipient delivery methods

Privacy aliases with optional PGP or S/MIME forwarding

Central S/MIME and PGP with an encrypted-PDF fallback

KDE mail with OpenPGP, S/MIME and contact-based crypto preferences

Email-client tracker controls with PGP and S/MIME options

A Mutt-derived terminal client with documented encryption configuration