The Coordination Center for TLD .RU/.РФ and Поддерживаю.РФ conducted a study to assess the level of support for internationalized email addresses (EAI) by mail servers specified in the MX resource records of second-level domains registered in the national domain zones .RU and .РФ. Resource records of this type point to servers that process email for domain names. The study tested support for the SMTPUTF8 extension of the SMTP protocol. The presence of support for the SMTPUTF8 extension on email server announces the ability to work with internationalized email addresses, in particular, the ability to send and receive letters using email addresses written in Cyrillic characters.
According to the 2024 Study, almost 590,000 registered second-level domain names in the .RU zone have an MX resource record pointing to a mail server with support for the SMTPUTF8 extension, while there are about 26,000 such domains in .РФ. At the same time, MX records of 261,229 domain names in .RU and 4,965 domain names in .РФ point to productive mail servers.
As part of the study, 17,962 unique mail servers were found in the .RU zone announcing support for the SMTPUTF8 extension, and 1,389 such servers in the .РФ zone. Most mail servers with SMTPUTF8 support use open source software: in the .RU zone - Postfix (32%) and Exim (30%), in the .РФ zone - Exim (57%) and Postfix (18%). The most popular mail services whose servers announce support for SMTPUTF8 and are indicated in the MX records of the studied domain names were Mail.Ru and Gmail: in the .RU zone - 63% and 11%, respectively, in the .РФ zone - 13% and 10%.
Compared to the data of 2022, there is an increase in the number of domain names with an MX record indicating a productive mail server with SMTPUTF8 support: in the .RU zone - by 230%, in the .РФ zone - by 59%. The number of unique mail servers with SMTPUTF8 support increased in the .RU zone by 53%, in the .РФ zone - by 59%. The number of mail servers with SMTPUTF8 support using open source software also increased: in the .RU zone - Exim by 127%, Postfix by 30%; in the .РФ zone – Exim by 117%, Postfix by 12%.
“The number of email servers that support the SMTPUTF8 extension of the SMTP protocol is growing every year. This indicates that the implementation of the EAI standard continues, and more and more mail service providers are providing users with the ability to work with Cyrillic email. Basically, such servers use open source software, so we would like to see efforts in this area from commercial software manufacturers,” Maria Kolesnikova, Head of the Поддерживаю.РФ, said.
The study was conducted based on data for February 2024. The full text of the study is published on the website of the Coordination Center for TLD .RU/.РФ.
Поддерживаю.РФ was created by the Coordination Center for TLD .RU/.РФ in 2020 to mark the tenth anniversary of the Russian top-level domain .РФ. It is designed to help software developers implement full support for Cyrillic domain names and email addresses in their products, and system administrators to correctly select and configure software with such functionality.
The project website contains Russian-language documentation on working with internationalized domain names (IDN) and email addresses (EAI), including standards and modern practices for processing them in software, as well as a constantly updated catalog of software products indicating their current IDN and EAI support status.
Information partners of the project: Internet portal D-Russia.ru, information and analytical portal DigitalReport, Internet portal "Mobile Telecommunications", RANS, scientific and technical journal "Vestnik Svyazi", journal "BIT.Business&Information Technologies" and "System Administrator" journal.
