Test on correctness of Cyrillic domain names display

We have tested web interfaces of the major mail services with respect to correct operation with Cyrillic domain names. The test consisted of 2 parts:

• An attempt to send a mail to the address in which a domain name is indicated in national alphabet characters (mailtest@пример.испытание);
• An attempt to send a mail to the address in which a domain name is converted to punycode (mailtest@xn--e1afmkfd.xn--80akhbyknj4f)

The findings of investigation are shown in the table. The first setting is the result of the first test and the second setting the result of the second test (in square brackets).

As we can see, only yandex.ru fully passed the test and gmail.com fully failed it. Other services managed to send an e-mail at least to the address converted to punycode.