The list of public IP addresses belonging to Fastmail

An IP address (Internet Protocol address) is a unique number assigned to each device connected to the Internet. It is used to identify and locate devices within a network.

There are two main versions of IP addresses:

1. IPv4 (Internet Protocol version 4): IPv4 addresses are represented as a series of numbers ranging from 0 to 255, separated by dots. For example: 149.28.157.142

2. IPv6 (Internet Protocol version 6): IPv6 addresses are represented as a hexadecimal string, separated by colons. For example: 2004:0db8:85a5:0000:0000:8a7e:0370:8334.

Each device that connects to the Internet, such as computers, smartphones, or servers, is assigned a unique IP address to facilitate communication and identification on the network. IP addresses enable the localization and identification of each device within the Internet network.