Swisssign - renewal of S/MIME Silver certificates

Swisssign informs that S/MIME certificates generated between July 15 2025 and April 17 2026 have a formal error as viewed by the CA/Browser forum as the regulatory body on certificates. According to Swisssign, the formal errors are not a security risk.

Affected certificates (of type “SwissSign Personal S/MIME E-Mail ID Silver”, ie domain validated certificates) will be revoked by Swisssign on April 22 2026 at 15:00 CET.

The lifecycle of certificates of customers using SEPPmail appliances (and therefore also seppmail.cloud customers) is fully automated, so the process should be transparent in most situations.

Given the scale of the renewal activity it would not come unexpected if some customers would experience performance issues at Swisssign (either on their portal or in our MPKI connector to their servers).

SEPPmail will closely monitor the situation at Swisssign and use this channel to provide additional updates as and if needed.