The tone of your follow-up email can make or break your chances of getting a response. You want to sound respectful, professional, and courteous, not demanding, rude, or aggressive. Use positive and polite language, such as "please", "thank you", "I appreciate", and "I hope". Avoid using negative or accusatory words, such as "urgent", "reminder", "overdue", and "you failed". Also, avoid using all caps, multiple exclamation points, or emoticons, as they can come across as unprofessional or emotional.