RainLoop is widely considered no longer actively maintained upstream. Security posture should assume elevated risk: isolate aggressively and plan migration to a maintained webmail stack.
¶ 1) Treat deployment as legacy and high-risk
- Restrict RainLoop access to VPN/internal networks whenever possible.
- Keep WAF/rate-limit rules in front of login/admin routes.
- Do not expose admin panel publicly.
- Define migration timeline to maintained alternatives (for example Roundcube).
¶ 2) Protect admin panel and data directory
- Change default admin URL path and enforce HTTP auth or SSO in front of it.
- Keep RainLoop data directory (
_data_) outside web root.
- Restrict filesystem permissions so web user can only access required paths.
- Disable directory listing and direct file access under app data paths.
¶ 3) Harden backend mail and database access
- Use TLS-only IMAP/SMTP endpoints.
- Store mail server credentials encrypted or in restricted config files.
- Restrict outbound connections to approved mail hosts only.
- Rotate service credentials periodically.
¶ 4) Monitoring and incident controls
- Alert on failed admin login spikes and unknown IP logins.
- Audit plugin/custom code changes aggressively.
- Back up config and user data with encryption.
- Run periodic vulnerability scans against exposed RainLoop endpoints.
¶ Verification commands
grep -R "admin\|data\|imap\|smtp" /var/www/rainloop /etc/rainloop 2>/dev/null | head
sudo find /var/www/rainloop -maxdepth 3 -type d -name '_data_' -ls
sudo ss -tulpn | grep -E ':443|:80'
- RainLoop repository: https://github.com/RainLoop/rainloop-webmail
- RainLoop maintenance discussion: https://github.com/RainLoop/rainloop-webmail/issues/2162
- RainLoop security-related issue history: https://github.com/RainLoop/rainloop-webmail/issues