Every IP address or domain used to send an email is tracked by reputation-related organizations. They each assign their own score, with an unique & advanced algorithm.
Some organizations test reputation on a scale up to 100. This is the case with Return Path, a huge player in the sector. Others, like Cisco's SenderBase, will instead give you rating (good, neutral or bad).
ISPs, email services (Gmail, Outlook, Yahoo!, etc.) and routers use these scores to guide their deliverability choices.
Reputation score and deliverability
Don't get obsessed with your reputation scores. They do have a big impact on your deliverability, but they are much more difficult to analyze and exploit. Algorithms are always evolving. This can explain a drop in your score, but not in your ability to deliver.
Reputation, and the scores that go with it, are only a reflection of your sending habits. Along with your subscriber's engagement.
We'll help you improve those scores. Ensuring a good reputation for our clients is part of our job.
IPR (Inbox Placement Rate)
This is a slightly stricter deliverability rate. It only takes into account the ratio of emails actually delivered to the inbox.
Inbox Placement Rate Formula
Inbox Placement Rate = (Volume sent - Bounces ) - (Spam + Lost emails) / Volume sent
Master the subject of reputation in email
If you send from a shared IP, you and the other users of the IP will build its reputation together. This can be an advantage of using an email provider. Whatever routing method you use, don't panic. Any email platform worthy of the name takes care of monitoring the actions of all its users. It will take active measures against those who have malicious behaviours. Those behaviours can endanger the reputation of the IP, which needs protection. That allows the activities from the IP to flow easily.
For your reputation, you must maintain your mailing lists when you encounter bounces. You will send a very negative message if you persist in using addresses that do not respond.