Email Glossary

IP Warmup

IP warmup is the process of slowly ramping up email volume on a new or unused IP address. Mailbox providers are cautious about new IPs with no sending history. Starting with low volumes to engaged recipients and gradually increasing builds the IP's reputation. Dedicated IPs require warmup, while shared IPs are already established.

IP Warmup vs Domain Warmup

Both are important but serve different purposes:

  • IP warmup establishes the reputation of the sending server
  • Domain warmup establishes the reputation of the sending brand

In modern email infrastructure, domain warmup is increasingly important because mailbox providers track domain reputation independently of IP. However, dedicated IPs still require their own warmup process to avoid being flagged as suspicious new senders.

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