CVE-1999-0429: The Lotus Notes 4.5 client may send a copy of encrypted mail in the clear across the network if the user do...

Security readout for executives and security teams

Lotus Notes 4.5 could transmit a plaintext copy of an "encrypted" email across the network when the user had not enabled the "Encrypt Saved Mail" preference. Users believed their message was protected end to end, but a copy still traversed the network unencrypted, exposing sensitive content to anyone able to observe traffic between the client and the mail server. Extremely limited in 2026. Lotus Notes 4.5 is decades out of support and unlikely to be present in modern environments. Residual exposure exists only where legacy Notes 4.x clients still operate on unmonitored network segments with unencrypted mail routing. Low priority for modern enterprises. Treat as a legacy hygiene item: confirm no Lotus Notes 4.x clients remain in use. If any are found, it signals a broader unsupported-software risk that warrants a migration decision rather than a targeted fix. Mitigation focus: Retire any remaining Lotus Notes 4.x clients and migrate to a supported HCL Notes or modern mail platform.; Where legacy Notes clients must persist, enable the "Encrypt Saved Mail" preference on every client profile.; Require TLS on all mail transport paths so client-to-server traffic is not readable on the wire..

Prepared

Jul 12, 2026, 01:14 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.