Email ports
Overview
Mail ports handle credentials and message content. Require TLS, disable open relays, and restrict submission ports to authenticated users.
Ports in this category26
Range coveredAll registry ranges
All Email port numbers
Every port below is assigned to this category in the registry or by a widely used convention. Open a port for its check and block commands, risk rating and troubleshooting notes.
| Port | Service | Transport | Risk | Description |
|---|---|---|---|---|
| 24 | Unnamed service | TCP / UDP | Standard/Low | any private mail system |
| 25 | SMTP | TCP / UDP | Medium | Simple Mail Transfer |
| 50 | RE-MAIL-CK | TCP / UDP | Standard/Low | Remote Mail Checking Protocol |
| 58 | XNS-MAIL | TCP / UDP | Standard/Low | XNS Mail |
| 110 | POP3 | TCP / UDP | Medium | Post Office Protocol - Version 3 |
| 143 | IMAP | TCP | Medium | Internet Message Access Protocol |
| 158 | PCMAIL-SRV | TCP / UDP | Standard/Low | PCMail Server |
| 174 | MAILQ | TCP / UDP | Standard/Low | MAILQ |
| 209 | QMTP | TCP / UDP | Standard/Low | The Quick Mail Transfer Protocol |
| 220 | IMAP3 | TCP / UDP | Standard/Low | Interactive Mail Access Protocol v3 |
| 406 | IMSP | TCP / UDP | Standard/Low | Interactive Mail Support Protocol |
| 465 | SUBMISSIONS | TCP / UDP | Standard/Low | Message Submission over TLS protocol |
| 505 | MAILBOX-LM | TCP / UDP | Standard/Low | mailbox-lm |
| 587 | SUBMISSION | TCP / UDP | Standard/Low | Message Submission |
| 993 | IMAPS | TCP | Standard/Low | IMAP over TLS protocol |
| 995 | POP3S | TCP / UDP | Standard/Low | pop3 protocol over TLS/SSL (was spop3) |
| 3007 | LOTUSMTAP | TCP / UDP | Standard/Low | Lotus Mail Tracking Agent Protocol |
| 3905 | MUPDATE | TCP / UDP | Standard/Low | Mailbox Update (MUPDATE) protocol |
| 4069 | MINGER | TCP / UDP | Standard/Low | Minger Email Address Validation Service |
| 5729 | OPENMAIL | TCP / UDP | Standard/Low | Openmail User Agent Layer |
| 5755 | OPENMAILG | TCP / UDP | Standard/Low | OpenMail Desk Gateway server |
| 5757 | X500MS | TCP / UDP | Standard/Low | OpenMail X.500 Directory Server |
| 5767 | S-OPENMAIL | TCP / UDP | Standard/Low | OpenMail Suer Agent Layer (Secure) |
| 11997 | WMERECEIVING | SCTP | Standard/Low | WorldMailExpress |
| 11998 | WMEDISTRIBUTION | SCTP | Standard/Low | WorldMailExpress |
| 11999 | WMEREPORTING | SCTP | Standard/Low | WorldMailExpress |
Other categories
Authentication and access 19Caching and in-memory stores 10Containers and orchestration 10DNS and naming 10Databases 54Development servers 13Directory services 14File transfer and sharing 27Gaming 6Infrastructure and administration 30IoT and device telemetry 7Message queues and streaming 17Monitoring and metrics 29Networking and proxies 31Printing 19RPC and service APIs 14Remote access 29Time synchronization 10VPN and tunnelling 10Voice and real-time media 29Web and HTTP 62Windows networking 14
Primary data: IANA Service Name and Transport Protocol Port Number Registry, plus clearly marked community conventions.
Last reviewed 2026-10-30 · Methodology · About · Privacy