993
imaps
TCP · 0x03E1
Port 993 — imaps
Port 993 carries Mail access over TLS over TCP. Being at or below 1023, only root may open it on Unix.
0–1023. On Unix only root may open one.
Where it sits in 65535
A port number is 16 bits, so it stops at 65535. The narrow band at the left is everything up to 1023.
065535
- Service
- Mail access over TLS (imaps)
- Kind
- Protocol
- TCP
- Range
- Well-known
- Root needed
- Yes
- Hexadecimal
- 0x03E1
- Binary
- 0000001111100001
- Two bytes
- 3 · 225
- Plain twin
- 143
Same kind
Sending mail out and fetching it back.
Ports next to it
How to read this
- A port number is 16 bits, so it runs 0 to 65535. There is no port 65536.
- Opening anything at or below 1023 needs root on Unix.
- Plain and encrypted often live on different numbers — 80 and 443, for one.
- Numbers like 3000 and 8080 were never registered; those are marked as custom.
Frequently asked questions
Q. What is port 993 used for?
Mail access over TLS (imaps) uses it, over TCP.
Q. Does opening port 993 need root?
Yes. It is at or below 1023, so on Unix only root may open it.
Q. Which range does port 993 fall in?
Well-known (0–1023). In hex it is 0x03E1.
Q. What does port 993 wrap?
It is port 143 wrapped in TLS.