NyProofpoint Protection Server 8.22.4: Patch 5807 leaves SMTP Client without a certificate
Patches 5806 and 5807 introduce a separate “SMTP Client” assignment under System > Certificates > Services in Proofpoint Protection Server 8.22.4. If it is set to “-none-”, Sendmail delivers without a TLS client certificate. Peers that validate certificates then reject messages, such as Exchange Online with 5.7.51 or a smarthost with “Relay access denied”. Here is how to check and fix it.
5. november 2026 Proofpoint 7 min read
