SmimeAudit

SmimeAudit is a web app (with an optional lightweight desktop agent) that continuously checks whether S/MIME will actually work across your real email clients and domains. It validates certificate chains, key usage, expiration, CRL/OCSP reachability, intermediate CA availability, and common client-specific pitfalls (Outlook/Exchange, Apple Mail, Gmail S/MIME, mobile MDM profiles). Instead of generic PKI dashboards, it runs practical “can I sign/encrypt to this recipient right now?” tests using safe synthetic messages and directory lookups, then produces actionable fixes: missing intermediates, wrong EKU, broken OCSP, mispublished certs, or incompatible algorithms. It also generates compliance-friendly reports and change alerts when a CA rotates intermediates or when DNS/Autodiscover/LDAP changes break discovery. This is not a magic security product; it’s an operational reliability tool for teams tired of S/MIME breaking silently and being blamed for it.