Port 993: IMAPS
Port 993 is IMAPS, encrypted IMAP mail access. Almost every mail client uses port 993 rather than plain IMAP on port 143.
TCPEmail EncryptedIANA assigned
| Port number | 993 |
|---|---|
| Service | IMAP over TLS |
| Protocol | TCP |
| Category | |
| Default encryption | Yes (TLS/SSH) |
Frequently asked questions
What is port 993 used for?
Port 993 is IMAPS, encrypted IMAP mail access. Almost every mail client uses port 993 rather than plain IMAP on port 143.
Is port 993 TCP or UDP?
Port 993 (IMAPS) uses TCP.
Is port 993 secure?
Yes. Port 993 carries encrypted traffic by default, so data in transit is protected.
Should I open port 993 on my firewall?
Only if you specifically need IMAPS. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.