IP Warming: Establishing a Reputation for New or Unused Email IPs
IP warming, also known as IP warm-up, is a process of gradually building a positive sending reputation for a new or previously unused email IP address. This involves:
- Starting with small email volumes from the new IP and systematically increasing the daily or weekly send volume over time, according to a set schedule.
- The goal is to develop the IP's identity and earn the trust of mailbox providers, increasing the chances of your emails being delivered to subscribers' inboxes.
Mailbox providers are wary of large email volumes from new or unfamiliar IPs, as this can indicate potential spamming. Implementing an IP warm-up before sending normal email volumes demonstrates to providers that you are serious about building a good sending reputation.
The IP Warm-Up Process:
- Complete a pre-warm checklist (e.g. set up PTR records, sign up for feedback loops, authenticate with DKIM, update SPF)
- Create an effective warming schedule based on your email program and current sending reputation
- Monitor performance carefully, adjusting daily volumes as needed
- Expect some deliverability issues in the first week, which may continue depending on email practices
The warm-up typically takes around 30 days, depending on factors like email volume, list quality, and send frequency. Services like AOL, Outlook, and Gmail often require longer warm-up periods.
By following best practices for IP warming, you can establish a trusted, reputable sending identity and improve email deliverability long-term.