What Is Sender Reputation?
Sender reputation is a score that email providers assign to your domain and IP address based on your email sending behavior.
Think of it like a credit score for email sending. The stronger your reputation, the more likely your emails will reach the inbox rather than the spam folder.
Email providers like Gmail and Outlook monitor factors such as bounce rates, spam complaints, and engagement to determine whether you’re a trustworthy sender. When you maintain a good sender reputation with SendLayer, your transactional emails are more likely to be delivered successfully.
How Does Sender Reputation Work?
Sender reputation works behind the scenes every time you send an email. Email providers constantly evaluate incoming messages to protect their users from spam and phishing attempts.
When you send an email through SendLayer, receiving servers evaluate multiple signals to determine whether your message should be delivered to the inbox, sent to spam, or rejected outright. They look at your sending history, how recipients interact with your emails, and whether you follow email authentication best practices.
Major email providers, such as Gmail, use tools like Google Postmaster to track sender reputation metrics. These systems aggregate data from millions of emails to identify trustworthy senders.
What Factors Affect Sender Reputation?
Several key factors influence your sender reputation. Email providers weigh these differently, but they all contribute to whether your emails reach the inbox.
- Bounce rate – High bounce rates signal that you’re sending to invalid addresses. Email providers see this as a sign of poor list management. Learn more about hard and soft bounces.
- Spam complaint rate – When recipients mark your emails as spam, it directly damages your reputation. Keep your spam complaint rate below 0.1% to maintain good standing.
- Sending volume patterns – Sudden spikes in email volume look suspicious. Warming up your domain with gradual increases is essential for new senders.
- Content quality – Using spam trigger words or deceptive subject lines can trigger spam filters.
How Can I Improve My Sender Reputation?
Improving your sender reputation requires consistent attention to email best practices. Here are the most effective strategies:
- Maintain clean email lists – Use a suppression list to prevent sending to addresses that have bounced or complained.
- Warm up new domains – If you’re sending from a new domain, gradually increase your sending volume over several weeks.
- Monitor your metrics – Track bounce rates, spam complaints, and engagement metrics regularly.
- Send wanted emails – Only send to recipients who have explicitly opted in to receive your messages.
- Use a reliable email service – Services like SendLayer actively monitor spam complaints and bounces to protect your reputation, and provide infrastructure that’s already trusted by major email providers.
- Follow platform-specific guidelines – Different providers have different standards. Check out our guides for Outlook deliverability and Gmail deliverability.
Remember that building a good sender reputation takes time. There’s no quick fix, but consistent good practices will steadily improve your deliverability.
That’s it! Now you know how sender reputation works.
Ready to protect and improve your sender reputation? Check out these resources: