How can establishing a good reputation with ISPs improve e-mail deliverability?

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Answer: Most Internet service providers have systems in place to scan incoming messages individually for viruses and spam. The messages are then checked against black lists and evaluated with other attributes. Reputation is a newer criterion that ISPs are using to evaluate mail. A sender’s reputation is determined when ISPs request the sender’s reputation score from a central, third-party reputation database.

While reputation management can decrease the amount of spam received by ISPs, it also means that senders must be able to implement a variety of specific sending rules to comply with each ISP’s requirements and be able to facilitate header markups to incorporate third-party accreditation solutions.

Some e-mail solutions readily accept new standards to adapt easily to changing ISP sending environments. Less flexible solutions make it more difficult to comply with ISP requirements, which can inadvertently damage a sender’s reputation if the company is using poor or unchecked sending practices.

Complying with individual ISP “throttling” requirements—the speed and volume at which an ISP will accept your e-mail—is a key factor in maintaining a good reputation. As a marketer, you should know if your e-mail platform (either in-house or through an e-mail service provider) allows control over settings such as total outbound connections, total message volume and volume ramping, and gives senders a way to match their sending practices to each ISP’s requirements, which change on a regular basis.

Senders should also be aware that a vast database of reputation data based on the global sending practices of thousands of companies was collected recently and published by anti-spam and accreditation vendors. This report provides ISPs with another way to filter e-mail by producing a “gray list” of senders. ISPs will make judgment calls based on the sending history published on this report to determine whether to send or block e-mail from unknown gray-listed senders.

Establishing a good reputation with ISPs is vital to deliverability. To protect your company’s reputation, consider doing the following:

  1. Use throttling to insure that you are not over burdening ISPs by sending too many messages too fast. If you use an ESP, make sure they provide you with the reporting to understand exactly how each ISP treats your mail.
  2. Contract with a third-party accreditation service that certifies sender policies and practices and makes those certified lists available to the ISPs.
  3. Depending on the type or volume of mail you are sending, establishing an in-house ISP relations team can help ensure that your mailing practices and reporting are contributing to maintaining a good reputation and relationship with each ISP.

Barry Abel is VP-field operations for Message Systems (, an e-mail software solutions provider for ESPs, ISPs and large enterprises.

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