Port 58XNS Mail

Xerox Network Systems (XNS) Mail is a legacy protocol designed by Xerox to facilitate electronic messaging within its proprietary network architecture. Developed in the late 1970s and early 1980s, XNS Mail was foundational for early email communication in Xerox's internetworking environment prior to widespread TCP/IP adoption..

transport
tcp · udp

2 transports registered

in transit
cleartext

payload readable on path

assignment
official

registered with iana

risk
4/10

caution

lookups
8,829

rank 567 of 993 · top 57%

Technical Details

what runs on :58

XNS Mail functions as part of the Xerox Network Systems protocol suite, which was one of the earliest comprehensive network architectures. Utilizing various XNS protocols like IDP (Internet Datagram Protocol) and SPP (Sequenced Packet Protocol), XNS Mail enabled reliable delivery of email data between machines on an XNS network.

It operates over both TCP and UDP on port 58, facilitating message transport and control signaling. Unlike modern, application-layer email protocols built atop TCP/IP (e.g., SMTP), XNS Mail is tightly coupled to the XNS stack's unique routing, addressing, and transport mechanisms. Its architecture was designed to work seamlessly within corporate Xerox environments.

Due to its deep integration with the XNS suite and non-standard design, interoperability with TCP/IP networks is limited. As Xerox ceased support, the protocol has become obsolete, replaced by Internet-standard email protocols.

Security Information

exposure of :58

risk score

4/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

email averages 3.9 across 42 ports — this one sits 0.1 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

Common Vulnerabilities:

  • Lack of encryption makes email contents susceptible to interception by network sniffing.
  • Limited authentication mechanisms increase risk of spoofing or unauthorized access.
  • Because of its age and obscurity, it might have unpatched flaws or buffer overflows known only through legacy documentation.

Common Mitigations:

  • Replace or disable XNS Mail if still operational.
  • Segment legacy systems running XNS Mail from core networks.
  • Use network monitoring to detect unexpected traffic on port 58.
  • Employ strict access controls and firewalling to block unused legacy protocols.

Related Ports

all 42 in email

the 8 most looked-up other ports in email — 42 ports carry that label.

portservicerisk
:143IMAPcaution
:995POP3Scaution
:109POP2caution
:2096cPanel SSL Webmailsafe
:110POP3caution
:993IMAPScaution
:1352Lotus Notes RPCcaution
:24Private Mailcaution

risk mix of the 8 listed

  • safe13%
  • caution88%

3 of 8 encrypted