IP Warming: Establishing a Positive Reputation for Your Email IP
IP warming, also known as IP warm-up, is a process used to establish a positive reputation for a new email IP address or an IP that has been inactive for some time. This involves gradually increasing the volume of emails sent from the new IP over a set schedule, starting with small volumes and steadily ramping up.
The goal of IP warming is to develop your sender identity and gain the trust of mailbox providers, increasing the chances of your emails being delivered to your subscribers' inboxes. Mailbox providers are naturally suspicious of email traffic from unfamiliar or new IP addresses, as this can indicate potential spam. To protect their users, they may block large volumes of email from new IPs.
By implementing a structured IP warm-up process before sending normal email volumes, you can demonstrate to mailbox providers that you are serious about building a good sending reputation. This typically involves:
- Creating an effective warm-up schedule based on your email program and current sending reputation
- Carefully monitoring performance metrics
- Adjusting daily sending volumes based on the results
The IP warm-up process generally takes around 30 days, depending on factors like:
- The volume of emails you send
- The quality of your subscriber list
- How frequently you send emails
Expect some deliverability issues in the first week, which may continue depending on your email practices. Sending emails daily can help accelerate the warm-up process.
Platforms like AOL, Outlook, and Gmail often require a longer warm-up period compared to other mailbox providers. The best approach is to create a custom warm-up schedule tailored to your specific sending habits and business needs.
To ensure optimal deliverability, follow this gradual sending schedule when warming up a new IP address:
Day 0: Send 250 emails to your most engaged Gmail subscribers only.
Day 1: Send 500 emails.
Day 2: Send 1,000 emails.
Day 3: Send 1,000 emails.
Day 4: Send 2,500 emails.
Day 5: Send 2,500 emails.
Day 6: Send 4,000 emails.
Day 7: Send 7,500 emails.
Day 8: Send 10,000 emails.
Day 9: Send 12,500 emails.
Day 10: Send 15,000 emails.
Day 11: Send 18,000 emails.
Day 12: Send 21,000 emails.
Day 13: Send 25,000 emails.
Day 14: Send 25,000 emails.
Day 15: Send 30,000 emails.
Day 16: Send 35,000 emails.
Day 17: Send 40,000 emails.
Day 18: Send 45,000 emails.
Day 19: Send 50,000 emails.
Maintain a bounce rate under 5% at all times. If the bounce rate approaches 10%, pause sending and review your data and sending practices. Complaint rates should remain below 0.1% for any list.
If deliverability issues occur, pause or reduce sending volumes to allow spam filters to adjust. Stop sending to providers with policy blocks and troubleshoot the cause before resuming. For AOL issues, pause for at least an hour, identify and fix the cause, then resume slowly with close monitoring.
Ensure your bounce and complaint processing are working correctly. Check for accidental sends to suppression lists, the entire list, or large numbers of unengaged subscribers. If so, hold volumes steady for a few days before restarting the original warm-up plan, focusing on engaged subscribers.