ISPs use a variety of factors to calculate your sender reputation score. These include:
Email Bounce Rate: High bounce rates can indicate to ISPs that you're sending emails to invalid addresses. Spam Complaints: If recipients frequently mark your emails as spam, your reputation will suffer. Engagement Metrics: Low open rates and click-through rates can hurt your score. Blacklistings: If your IP address or domain is blacklisted, your reputation score will be negatively affected. Email Volume: Sending a large number of emails in a short period can raise red flags.