The webpages you mention use different encodings. The mail.ru page uses Cyrillic Windows-1251, the rinet.ru page uses Unicode UTF-8.
It may be that the mail.ru source is saved exactly as the server sent it, but your text editor didn't detect the encoding or doesn't support it at all. See if your text editor has an Encoding option or menu and try different encodings.
As a test, you can drag and drop the text file into your web browser. If the Russian text doesn't appear correctly, you can try different encodings. Depending on your web browser, you can use something like right-click → Encoding, or page menu → Encoding, or View → Encoding.
This test can help confirm if text editor isn't detecting the encoding, or if the text file's encoding was incorrectly converted when it was saved.