The mail.properties file is specific to you, your email and your own server… sharing someone else’s will do you no good.
Please read the documentation. https://github.com/blynkkk/blynk-server#enabling-mail-on-local-server
mail.smtp.auth=true
mail.smtp.starttls.enable=true
mail.smtp.host=smtp.gmail.com
mail.smtp.port=587
mail.smtp.username=YOUR_EMAIL_HERE
mail.smtp.password=YOUR_EMAIL_PASS_HERE