IP Warming

Maybe Joan Jett didn’t care about a bad reputation, but when it comes to mailings, you definitely should!

IP warming attempts to establish a positive sender reputation from an IP address that has little to no recent sending history. Establishing a good reputation before sending a high volume mailing is highly recommended because if an IP address’s reputation is not in place (i.e. “warmed”), mail receivers may classify the mailings as spam and block them.

There is no set method to guarantee a positive sender reputation, but there are some steps you can take to help prevent your mailing from being marked as spam or worse!

Staggering Your Mailing

One critical step when sending from a new IP address is to slowly introduce mailing traffic to receivers. If your list is more than 100 subscribers but less than 10,000, spread out the mailing over the course of a few days. If the list is larger than 10,000 recipients, send over the course of a week or more (the Informz "distributed" option allows easy control of these functions).

Once you have established your reputation, continue to send at a regular, consistent volume. If there is a spike or dip in volume, this may also act as a spam trigger. Remember, receivers like predictable sending patterns!

Additional IP Warming Considerations

The following actions can help set a good reputation:

  • Authenticate your sending domain(s) through Informz before sending your first mailing (make sure your SPF and DKIM records in place).
  • Create a target group which contains your most recent engaged subscribers (those that have been sent an email within the past three months and have had open/click activity).
  • Ensure that your list only contains subscribers who have opted in to receive the mailing (if necessary, remove opt-outs and unsubscribers).

Once you begin to send, make sure to check your mailing reports regularly to see if any blocks or bounces are occurring. If you are seeing less than desirable results, you may need to slow your sending volume and frequency and troubleshoot (look at bounces, domain blocks, unsubscribe reasons, complaints, and content).

If you are noticing positive results in your reporting, you may slowly increase your daily send rate.

Example Scenario

One of the best ways to understand the best practices for building a positive sender reputation is following a step-by-step example of staggered mailing. Below is an example scenario of how you might schedule your mailing to a list of 10,000 recipients.

Remember, this is only an example – following this pattern does not guarantee a positive reputation! However, if you monitor your delivery numbers (blocks, bounces, unsubscribes, etc.) with each day’s mailing, you have a better chance of establishing and keeping a good standing with different mail receivers.

Day 1: Send a mailing to 1,000 of your most engaged subscribers (make sure that they have received a mailing from your organization within the past three months). Use the “distributed” option with this mailing to send it over a 24-hour period.

Day 2: View your mailing activity report to see if you are experiencing any blocks or bounces from your first send. If not, increase your next mailing to 2,000 recipients and again use the “distributed” option to send your mailing over a 24-hour period. (If you are experiencing any blocks or bounces, address your concern with your advisor and do not send your next mailing until you have adjusted your plan!)

Day 3: View your mailing activity report (as above). If your statistics are good (little or no bounces/blocks), increase your send to 3,000 recipients and use the “distributed” option to send your mailing over a 24-hour period.

Day 4: View your mailing activity report (as above). If your statistics are good (little or no bounces/blocks), send to your remaining 4,000 recipients and use the “distributed” option to send your mailing over a 24-hour period.

Day 5: Based on your delivery results from your mailings, decide whether or not to send at your planned volume. Remember, it is a best practice to continuously check your delivery numbers for each mailing and address any issues immediately. Additionally, always use the “distributed” option to increase your chances of delivery.

Final Thoughts

Just like dealing with any type of reputation, it can actually take more work to build that trust again if it is lost! IP warming may sound like a lot, but it is far better to start on the right foot.