A new security warning has been issued by the ShadowServer Foundation, alerting millions of email hosts that their servers are exposing user passwords and message content in plain text. The non-profit organization is sending warning notifications to affected email hosts and advising users to check if Transport Layer Security (TLS) is enabled on their accounts.
According to the Shadowserver Foundation, scans have confirmed that millions of email services are operating without TLS encryption, making usernames and passwords vulnerable to hackers who can “sniff” out the data. The organization has identified 3.3 million POP3 email hosts and a similar number of IMAP email hosts, although some overlap exists between the two.
To mitigate this threat, users are advised to check with their email service provider to ensure TLS is enabled and using the latest version of the protocol. However, users on Apple, Google, Microsoft, and Mozilla email platforms do not need to worry as these services already enable TLS and use the latest versions. The Shadowserver Foundation has also provided vulnerability reports for both POP3 email servers and IMAP email hosts on their website.
Source: https://www.forbes.com/sites/daveywinder/2025/01/03/new-email-warning-for-millions-passwords-and-mail-content-exposed