Since "mail.ru" is a Russian service, your text file might include Cyrillic characters.
Ensure the file is saved in UTF-8 encoding . If characters appear as gibberish (mojibake), try changing the text editor settings to recognize Russian characters.
Use ALL CAPS sparingly for emphasis rather than bolding.
You can use an online Russian keyboard to type Cyrillic letters phonetically using a standard QWERTY layout. 4. Text Editor Recommendations
Manually add a carriage return after every 50–60 characters to prevent the text from stretching too wide on different screens.
Keep it on a single line with no extra spaces or hidden characters unless specified by the platform. 2. Effective Plain-Text Email