Is port 2525 (SMTP Alternate) dangerous?

Port 2525 is classified as medium risk. It is commonly exposed but consider using encrypted alternatives where available and monitor activity.

Should port 2525 be open on my firewall?

Port 2525 can be open but should be monitored closely. Keep the service updated and prefer encrypted alternatives where available.

What transport protocol does port 2525 use?

Port 2525 (SMTP Alternate) uses the TCP transport protocol and falls under the Email category.

:2525 (TCP)

SMTP Alternate

Medium Risk

TCP — 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.

Related Ports — Email

24 Private Mail System 25 SMTP 26 RSFTP 50 RE-MAIL-CK 58 XNS-MAIL 109 POP2 110 POP3 143 IMAP

Related Terms

ARP FTP HTTP ICMP IMAP NTP