When you get a new dedicated IP address for email sending, it has no reputation. Mailbox providers are skeptical of unknown IPs because spammers frequently rotate through new addresses. IP warming proves you are a legitimate sender by starting small and scaling up over 2 to 6 weeks.
A typical warming schedule starts with 200 to 500 emails per day in week one, sending only to your most engaged recipients (people who opened or clicked an email in the last 30 days). Volume doubles each week while maintaining strong engagement metrics. By week four or five, you are at full volume with an established reputation.
The key to successful warming is audience selection. During the warming period, you want the highest possible engagement rates. Send to people who regularly open your emails. Avoid cold segments, old lists, or unengaged contacts until your reputation is established. One bad send during warming can set you back weeks.
Some situations require warming: migrating to a new MAP (new sending infrastructure), switching from shared to dedicated IP, adding a new dedicated IP due to volume growth, or restarting a dormant email program. Shared IPs do not require warming because they inherit the collective reputation of all senders on the IP.
Most MAPs have warming guidance or automated warming features. Marketo, HubSpot, and Salesforce Marketing Cloud all provide documentation on warming schedules. Follow their recommendations and monitor deliverability metrics closely during the warming period. If bounce rates spike or engagement drops, slow down and adjust.