Port993— IMAP over TLS
Le port 993 permet l’accès aux boîtes aux lettres IMAP via TLS implicite. Il sert à lire et synchroniser le courrier, pas à le soumettre via SMTP.
Registry assignments, software defaults and local listeners are different things. A port number alone does not identify or secure a service.
Configuration and troubleshooting
Vérifiez qu’IMAP est activé, que le certificat correspond au nom du serveur et que le client utilise TLS implicite. Examinez ensuite l’authentification et la politique d’accès à la boîte aux lettres.
Important limitations
Changer de port ne corrige ni des identifiants incorrects ni les droits sur la boîte aux lettres. Ne désactivez pas TLS pour contourner une erreur de certificat.
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.
Logiciels utilisant ce port (4 logiciels)
Community software entries: links are references, not individual verification.
IMAPSMail
IMAP over SSL/TLSSecurityMail
Conseils d’utilisation
- Avant d’utiliser le port 993, vérifiez qu’il n’est pas occupé par d’autres services
- En cas de conflit de ports, envisagez d’utiliser d’autres ports ou d’arrêter le service qui occupe le port
Questions fréquentes
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.
En bref
- Port
- 993
- Protocole
- TCP
- Catégories
- E-mail et messagerie
- État d’utilisation
- 4 logiciels utilisant ce port
Ports associés
Besoin d’aide ?
Si vous trouvez des informations incorrectes ou souhaitez en ajouter, veuillez proposer une correction.
Proposer une correction