Asia Pacific is home to approximately 4.3 billion people, where over 2,300 languages are spoken in this incredibly diverse region. Most languages here are not based on the Latin script, which makes their written characters unique. Despite this, many aspects of online communications and online presence, such as domain names for company websites and personal email addresses, rely solely on English alphanumeric characters.

While previously email addresses are restricted to the American Standard Code for Information Interchange (ASCII) standard, Email Address Internationalization (EAI) is an open standard for allowing non-ASCII characters, such as Arabic, Chinese, Cyrillic or Devanagari, in email addresses. All of these non-Latin characters from various writing systems are non-ASCII based, and are encoded in Unicode, which “translates” our texts into numbers that computers can comprehend. Unicode characters allow us to create email addresses in languages other than English, and enable us to communicate and share information in our local languages at both interface and transport levels.

The Rise of Email Address Internationalization (EAI)

As the world becomes more connected, the need to use domain names and email addresses in local languages and scripts also continues to rise. EAI adoption has been growing in recent years, according to a Universal Acceptance Steering Group (UASG) report, as of May 2021, around 9.6% of email domains now support Email Address Internationalization (EAI), marking a noteworthy improvement from previous years. This progress indicates that EAI support is becoming more prevalent, ultimately making it simpler for individuals across the globe to utilize email addresses in their preferred languages and scripts.

Despite EAI standards having been published by the Internet Engineering Task Force (IETF) for several years, it has yet to reach the same level of deployment and acceptance as traditional ASCII email addresses. Although some popular email service providers like Gmail and Microsoft Outlook have implemented and adopted EAI, they have yet to turn on the capability for users to register their user names in different native languages, and many other email providers and clients altogether do not support non-Latin characters. This leaves most people with little choice but to continue to use Latin-based email addresses.

The Challenges of Multilingual Communication in EAI

Despite the potential benefits of internationalized email addresses, the adoption rate remains relatively low, because the process of implementation is not as straightforward as it may seem.

A feature of the email ecosystem is that it is decentralized and therefore somewhat fragmented, because it is composed of a vast number of service providers and clients, each with its own unique technical implementations based on local network requirements and limitations. This creates compatibility issues and interoperability challenges, making it tedious for users to send and receive emails across different email systems.

For instance, if an email is sent with an email address with Chinese characters (such as info@网站.亚洲) from an EAI-supporting server to a non-EAI-supporting server, the Chinese characters in the email address may be converted to a Punycode format that consists Unicode characters transcoded into the letter–digit–hyphen (LDH) subset of ASCII. Turning ‘info@网站.亚洲’ to ‘info@xn--5tzm5g.xn--jlqs6k2ud492a’ on your screen instead. This conversion process can often result in the email address appearing differently in the recipient’s inbox than it did in the sender’s inbox. Or worst yet, the message could be rejected by the receiving server altogether.

Similarly, if an email is sent with an email address with non-ASCII characters from non-EAI supported server to an EAI-supported server, the email may simply be rejected or may not even be delivered to the intended recipient. This is because the non-EAI-supported server does not understand how to handle email addresses with non-ASCII characters, and this poses issues with the transmission of the email message.

EAI Progress and Remaining Challenges

To prevent email delivery failures and ensure that messages are correctly transmitted and displayed in their intended language or format, it is crucial for email providers and servers to implement the EAI standard universally. However, non-EAI-supporting servers like Sendmail (default configuration) remain a critical component of many email systems in enterprise environments.  In 2013, Sendmail held a significant market share of 10% among all mail servers on the internet, ranking ahead of even Microsoft Outlook at the time. Despite the passage of a decade, Sendmail has managed to maintain its position among the top three mail servers, although its market share has seen a noticeable decline, dropping to 3.58% according to the 2023 survey.

Sendmail is a mail transfer agent (MTA) that was first developed in the 1980s to route and deliver email messages. It is responsible for accepting outgoing email messages from the local host or client and delivering them to the recipient’s mail server, and accepting incoming email messages from other mail servers and delivering them to the local recipient’s mailbox. Sendmail is known for its flexibility and powerful features, but it can also be complex to configure and maintain. Additionally, the process of upgrading or replacing it can be complicated and costly, particularly for larger organizations, which poses a significant challenge to achieving universal acceptance (UA) of EAI.

Overcoming the Hurdles of EAI

By default, Sendmail supports ASCII-based email addresses, which are limited to the Latin alphabet and a few special characters. However, it is possible to configure Sendmail to support EAI by enabling support for SMTPUTF8, a Simple Mail Transfer Protocol (SMTP) extension that allows for the transmission of email addresses with the use of non-ASCII characters.

Given its widespread use, enabling EAI support in Sendmail is an important step toward implementing EAI across various email systems in the increasingly multilingual and multicultural business world. This is especially crucial for improving accessibility for non-English speakers, where the ability to process and route email messages containing Unicode-based email addresses is becoming increasingly important.

By enabling the use of one’s native language scripts in their email addresses, they can express their cultural and linguistic identity without the need to adopt an English-based email address. This reduces the need for translation and facilitates cross-cultural communication, as well as promotes greater inclusivity and diversity in online communication by enabling people to express their identities more fully.

In addition to the multilingual and multicultural benefits, the use of Unicode-based email addresses can also improve email security. Compared to traditional email addresses that use ASCII characters, Unicode-based email addresses use a wider range of characters that are more complex to replicate, making them less susceptible to phishing attacks. Therefore, it is crucial for more email service providers to become EAI or UA-ready in order to enhance email security and protect users from potential cyber threats.

Towards Universal Acceptance

The adoption of EAI is not just a matter of configuring Mail Transfer Agents (MTA) and ensuring compatibility between different systems that support EAI, but also support at the email client and server level, as well as in other parts of the email infrastructure. This highlights the need for a concerted effort by all stakeholders, including email providers, server administrators, and system integrators, to work together and overcome these challenges in order to achieve universal acceptance of EAI.

Universal Acceptance is a foundational requirement for a truly multilingual Internet. It is a technical requirement that ensures all valid domain names and email addresses, regardless of script, language, or character length, can be equally used by all Internet-enabled applications, devices, and systems. Adopting UA may have a positive impact on new gTLDs, by fostering competition, creating more consumer choices, and driving innovation in the domain name industry. 

To pave the way for a truly inclusive Internet of the future, it’s essential for internet systems and applications to treat all top-level domains (TLDs), including new generic TLDs (gTLDs) and internationalized TLDs, in a uniform manner. This entails the ability to recognize, validate, store, process, and display all domain names without any distinctions or biases. The present is the opportune time to take action toward achieving this goal, and be part of the movement toward achieving Universal Acceptance.


The Universal Acceptance Steering Group (UASG) is a group of stakeholders, including representatives from the Internet Corporation for Assigned Names and Numbers (ICANN), domain name registries, and other organizations, that advocates for the use of domain names and email addresses in all languages and scripts.

On March 28, 2023, the UASG, ICANN, global partners, and regional and local organizations come together to hold UA training, awareness, and strategy sessions are held to rally local, regional, and global communities and organizations to spread Universal Acceptance (UA) awareness and to encourage UA adoption with key stakeholders.