50
RE-MAIL-CK
Medium RiskTCP/UDP — Email
Port Overview
Port Number
50
Service Name
RE-MAIL-CK
Transport Protocol
TCP/UDP
Category
Email
Security Risk
Medium
Port Range
Well-Known (0-1023)
What is Port 50?
Remote Mail Checking Protocol. A legacy protocol that allows remote verification of mail addresses without sending a full message.
TCP/UDP
Email
Security Considerations
Port 50 (RE-MAIL-CK) is classified as medium risk. While this service is commonly exposed, consider using encrypted alternatives where available.
Recommendation: Keep the service updated. Monitor logs for unusual activity.