On February the 12th 2020 we disabled the deprecated protocols TLS 1.0 and 1.1 in Dovecot (POP3, POP3S, IMAP, IMAPS) and Postfix (SMTPS, SUBMISSION). Unauthenticated mail via SMTP on port 25/tcp does still accept >= TLS 1.0 . It is better to accept a weak encryption than none at all. **How to re-enable weak protocols?** Edit `data/conf/postfix/extra.cf`: ``` submission_smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 smtps_smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 ``` Edit `data/conf/dovecot/extra.conf`: ``` ssl_min_protocol = TLSv1 ``` Restart the affected services: === "docker compose (Plugin)" ``` bash docker compose restart postfix-mailcow dovecot-mailcow ``` === "docker-compose (Standalone)" ``` bash docker-compose restart postfix-mailcow dovecot-mailcow ``` Hint: You can enable TLS 1.2 in Windows 7.