The Coordination Center for TLD .RU/.РФ and the Поддерживаю.РФ project conducted another study to evaluate the level of support for internationalized email addresses (EAI) by mail servers listed in the MX resource records of second-level domain zones registered in the national top-level domains .RU and .РФ. These resource records point to servers responsible for processing email for domain names. The study checked whether mail servers announced support for the SMTPUTF8 extension of the SMTP protocol. Such an announcement indicates that a mail server can handle internationalized email addresses, including the ability to send and receive emails using Cyrillic-based email addresses.
In the .РФ domain, 45,720 domain names have MX records pointing to mail servers supporting SMTPUTF8, with 83% of these being serviced by the Timeweb mail provider. A total of 1,710 unique mail servers in .РФ advertise SMTPUTF8 support, with 66% running the Exim open-source mail software.
In the .RU domain, 492,212 domain names have MX records pointing to mail servers supporting SMTPUTF8, of which 43 percent are serviced by Timeweb and 34 percent by Mail.ru. A total of 21,422 unique mail servers announcing SMTPUTF8 support were identified in .RU – 36 percent use Exim, while 25 percent use Postfix.
Overall, the study recorded steady positive momentum in developing support for internationalized email in .РФ and .RU domains. Compared to 2024, the total number of domain names with at least one MX record pointing to a productive mail server supporting SMTPUTF8 increased more than eightfold in .РФ and by 88 percent in .RU. The number of unique mail servers announcing SMTPUTF8 support also grew: by 23 percent in .РФ and 19 percent in .RU.
“The consistent increase in the number of mail servers supporting SMTPUTF8, particularly in the Cyrillic .РФ domain, confirms that native-language email is becoming a norm rather than an exception. We hope that email service providers and software developers will continue implementing the EAI standard, with even more industry players joining the effort,” commented Maria Kolesnikova, head of the Поддерживаю.РФ project.
The study was conducted based on February 2025 data. The full report is available on the Coordination Center for TLD .RU/.РФ website.
