Solutional new logo (1)

Email address

Deel dit
" Terug naar Woordenlijst Index

An email[4] address is a unique identifier for an individual’s electronic mailbox, following a specific format of local-part@domain. The local-part, with a maximum length of 64 octets, represents the specific mailbox, while the domain, up to 255 octets, indicates the mail server. Email addresses are essential for communication via PCs, mobile devices, or webmail sites, and are often used for user validation on websites. However, a correct format doesn’t guarantee existence. Techniques like callback verification are used to verify mailbox existence. Emails are transmitted through the Internet[3] using the SMTP protocol defined in RFC5321 and 5322, with the SMTP client using the domain name[1] to locate the mail exchange IP address[2]. Further, the IETF has worked towards internationalizing email addresses, enabling the use of non-ASCII characters. The domain of the email address must meet strict rules, including a limit of 63 characters and the inclusion of letters, digits, and hyphens.

Terms definitions
1. domain name. A domain name is a text-based label that identifies internet resources such as computers and services. It serves as an indicator of ownership or control over a resource and provides an easily recognizable name for these resources. In structure, a domain name is made up of concatenated labels separated by dots, arranged in a descending hierarchy from right to left. Each label can contain 1 to 63 octets and the overall domain name should not exceed 253 ASCII characters. The Domain Name System (DNS) translates these domain names into IP addresses, helping to distribute web traffic across different servers. Domain names are organized into a tree structure, with Top-Level Domains (TLDs) such as .com, .org, .net at the highest level. The Internet Corporation for Assigned Names and Numbers (ICANN) oversees the allocation of TLDs and accredits domain registrars. Domain names can also be internationalized, with many registries adopting the Internationalized domain name (IDNA) system approved by ICANN. The domain name industry is subject to cyber threats like spoofing, but measures are in place for protection.
2. IP address ( IP address ) An IP address is a unique identifier assigned to each device connected to a network, enabling data to be sent and received accurately. It functions like a street address for the internet, marking the specific location of a device within a network. There are two versions of IP addresses: IPv4 and IPv6. IPv4, the older version, has 32-bit addresses, while IPv6 uses 128-bit addresses, offering a significantly larger number of possible addresses. IP addresses can be public or private, with private ones used within a local network and public ones used on the internet. Other key aspects include subnetting for routing efficiency, autoconfiguration for dynamic assignment, and potential conflicts from multiple assignment methods. IP addresses also play a significant role in routing and geolocation, determining the geographic position of devices. There are legal and regulatory aspects to consider, due to privacy concerns, and they are crucial in network configuration and troubleshooting.
Email address (Wikipedia)

An email address identifies an email box to which messages are delivered. While early messaging systems used a variety of formats for addressing, today, email addresses follow a set of specific rules originally standardized by the Internet Engineering Task Force (IETF) in the 1980s, and updated byRFC 5322 and 6854. The term email address in this article refers to just the addr-spec in Section 3.4 of RFC 5322. The RFC defines address more broadly as either a mailbox or group. A mailbox value can be either a name-addr, which contains a display-name and addr-spec, or the more common addr-spec alone.

An email address, such as, is made up from a local-part, the symbol @, and a domain, which may be a domain name or an IP address enclosed in brackets. Although the standard requires the local-part to be case-sensitive, it also urges that receiving hosts deliver messages in a case-independent manner, e.g., that the mail system in the domain treat John.Smith as equivalent to john.smith; some mail systems even treat them as equivalent to johnsmith. Mail systems often limit the users' choice of name to a subset of the technically permitted characters.

With the introduction of internationalized domain names, efforts are progressing to permit non-ASCII characters in email addresses.

" Terug naar Woordenlijst Index
Scroll naar boven