Return Path hosts a widely used and highly accurate blacklist, which is an official list of email server IP addresses that show activity resembling the activity of spammers. This evaluation is based on the percentage of email messages from a particular IP address that are considered unwanted or "spam" by individual recipients as well as email providers and filters through a variety of actions including, but not limited to, complaints, unusual volume patterns, and emails sent to spam traps and unknown email addresses.
Check Your Sender Score
Your Sender Score provides high-level insight into your sender IP reputation. Your email reputation is an indication of inbox potential – not your inbox delivery rate – and it’s only one of many data points you need to determine how mailbox providers may be filtering, blocking, or delivering your email to inboxes.
Click here to check your Sender Score and get a report for insights into how mailbox providers are filtering your email.