Reputation

It used to be that every potential client that called me up to ask me to help them with their delivery issues would tell me they weren’t a spammer. Over the last year or so that’s changed to telling me that they have a good reputation and don’t understand why they’re having delivery problems.
This leads me to believe that there is some confusion about what reputation is and what reputation is not.
Reputation is a shorthand term for a complex formula measuring the history of email from an IP address. Some reputation schemes measure the history of email containing a particular URL or domain.
Recipient domains measure a lot of things and use them at various points during the email transaction. Some measurements are integrated into a single value that is queried during the SMTP transaction. If the measurement is too bad, the email is rejected or rate limited. Other measurements are queried after the email is accepted by the ISP, and those values determine if an email is delivered to the inbox or the bulk folder.
There are a couple important things to remember about reputation.

• Reputation is not a fixed value. It will vary from day to day and from receiver to receiver.
• Reputation is exactly that: reputation. It measures the overall perception of an email sender.
• Poor reputation is a consequence of poor sending practices.
• Fixing sending practices repairs reputation.

ESPs, ISP Relations experts and delivery consultants can guide a sender through the process of repairing reputation. But the only thing that will actually improve reputation is changing sending practices.