2525
SMTP Alternate
Medium RiskTCP — Email
Port Overview
Port Number
2525
Service Name
SMTP Alternate
Transport Protocol
TCP
Category
Email
Security Risk
Medium
Port Range
Registered (1024-49151)
What is Port 2525?
Port 2525 is a commonly used alternate SMTP port for outbound email submission, particularly useful when ISPs block the standard ports 25 and 587. Many email service providers like SendGrid, Mailgun, and Postmark support port 2525 for SMTP relay. It is especially popular for cloud hosting environments where port 25 is blocked by default.
TCP
Email
Commonly Used
Security Considerations
Port 2525 (SMTP Alternate) 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.