Networking
Risk: Low
Port 993 — IMAPS (IMAP over SSL/TLS)
Port 993 is the secure, industry-standard port for IMAP over SSL/TLS, encrypting all client-server mail communication from the initial connection.
PORT NUMBER
993
PROTOCOL
TCP
DEFAULT PROCESS
dovecot, imapd
FIREWALL TARGET
993/tcp
Instant Terminal Fixes for Port 993
macOS & Linux Terminal
1. Check who is listening on port 993:
sudo lsof -i :993 || sudo ss -tulpn | grep ":993 "2. Kill process occupying port 993 (EADDRINUSE fix):
sudo systemctl stop dovecot3. UFW Firewall Allow rule:
sudo ufw allow 993/tcpWindows PowerShell (Admin)
1. Check listening port:
Get-NetTCPConnection -LocalPort 9932. Force kill process on port 993:
Stop-Service MSExchangeIS -Force -ErrorAction SilentlyContinue3. Docker Port Forwarding Mapping:
docker run -p 993:993 -d mailserver/docker-mailserver:latestCommon Error Encountered
Connection refused connecting to mail server IMAPS on port 993.
Security Advisory & Hardening
Standard secure email retrieval port. Enforce modern TLS 1.3 protocol and keep mail server SSL certificates automatically renewed with Let's Encrypt.
Frequently Asked Questions
Port 993 Questions & Answers
Common questions regarding default services, kill commands, and firewall configurations.
Port 993 is commonly used for IMAPS (IMAP over SSL/TLS). Port 993 is the secure, industry-standard port for IMAP over SSL/TLS, encrypting all client-server mail communication from the initial connection.