25
SMTP
Medium RiskTCP — Email
Port Overview
Port Number
25
Service Name
SMTP
Transport Protocol
TCP
Category
Email
Security Risk
Medium
Port Range
Well-Known (0-1023)
What is Port 25?
Simple Mail Transfer Protocol. The standard protocol for sending email between mail servers. Often targeted by spammers and requires proper authentication configuration.
TCP
Email
Commonly Used
Security Considerations
Port 25 (SMTP) 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.