포트993— IMAP over TLS
포트 993은 암시적 TLS를 통한 IMAP 사서함 접근을 제공합니다. 메일 읽기와 동기화를 위한 것이며 SMTP 메일 제출용이 아닙니다.
Registry assignments, software defaults and local listeners are different things. A port number alone does not identify or secure a service.
Configuration and troubleshooting
IMAP이 활성화되어 있는지, 인증서가 서버 이름과 일치하는지, 클라이언트가 암시적 TLS를 사용하는지 확인하세요. 그런 다음 인증과 사서함 접근 정책을 점검하세요.
Important limitations
포트를 바꿔도 잘못된 자격 증명이나 사서함 권한은 해결되지 않습니다. 인증서 오류를 우회하려고 TLS를 비활성화하지 마세요.
Read-only checks: run on the server host
Choose the commands for your OS. Check TCP and UDP separately. No result is not a lasting availability guarantee; inspect host and container separately.
Linux
sudo ss -ltnp 'sport = :993'macOS
sudo lsof -nP -iTCP:993 -sTCP:LISTENWindows PowerShell
Get-NetTCPConnection -LocalPort 993 -State ListenSources and review
Sources checked on:
This review covers the explanations and sources on this page, not your device or every community software entry below.
이 포트를 사용하는 소프트웨어 (4 개 소프트웨어)
Community software entries: links are references, not individual verification.
IMAPSMail
IMAP over SSL/TLSSecurityMail
사용 시 참고 사항
- 포트 993 사용 전에 다른 서비스가 점유하고 있지 않은지 확인해 주세요
- 포트 충돌이 발생하면 다른 포트를 사용하거나 해당 포트를 점유한 서비스를 중지하는 것을 고려해 보세요
자주 묻는 질문
What is port 993 used for?
Port 993 sits in the Email & Messaging category. This page lists the registered purpose and the software commonly associated with it; to see what is actually listening on a specific machine, check the process with ss/netstat.
Is port 993 TCP or UDP?
The registered protocol on this page is TCP. The same number behaves independently on each protocol: TCP may be listening while UDP is idle, so check them separately.
How do I check if port 993 is in use?
On Linux: sudo ss -tlnp 'sport = :993' for an exact port match. On macOS: sudo lsof -nP -iTCP:993 -sTCP:LISTEN. On Windows PowerShell: Get-NetTCPConnection -LocalPort 993 -State Listen. A listener counts as confirmed only when you can see the bind address and process name; without root/admin you will not see other users' processes.
Is port 993 secure? Should I open it in my firewall?
A port number has no inherent security — it depends on whether the listening service is correctly configured and whether it needs exposure at all. Keep loopback/internal-only services firewalled; where public access is required, pair it with source restrictions, VPN or authentication. The caution section on this page lists port-specific risks.