TCP 10023
Synopsis
- Postgrey (a greylisting policy server for Postfix) listens on TCP/10023 by default; Postfix queries it via the policy delegation protocol.
- Real deployments using this include Mail-in-a-Box and Proxmox Mail Gateway, where Postgrey runs on 127.0.0.1:10023 to provide greylisting during SMTP.
- Lantronix serial device servers (e.g., EDS/UDS series) expose each serial channel on TCP ports 10001 and up; on multiport models, TCP/10023 is the data socket for serial port 23, used to reach attached console/serial equipment.
- Security note: Exposed Lantronix data ports (including 10023 on multiport units) have been abused when left accessible with default credentials, allowing remote access to attached serial consoles.
Observed activity
Last 30 days
Detailed chart