Email IP Warmup Schedule

Definition

When you start sending from a new IP address, ISPs have no reputation data for it. Sending full volume immediately triggers spam filtering and blocking. An IP warmup schedule gradually increases daily send volume over 4-8 weeks, allowing ISPs to observe and build trust in your sending pattern.

Sample Schedule (100K Target)

Week	Daily Volume	Weekly Total
1	200-500	< 3,500
2	1,000-2,500	< 17,500
3	5,000-10,000	< 70,000
4	20,000-30,000	< 210,000
5	50,000-70,000	350,000-490,000
6+	Full volume	Target reached

Best Practices

• Warm up on a single IP before adding more
• Send to your most engaged subscribers first
• Maintain a consistent sending schedule (same days, similar volumes)
• Monitor deliverability metrics daily during the warmup period
• Avoid sending to purchased, rented, or unengaged lists during warmup

Why It Matters

A botched IP warmup can permanently damage the IP's reputation, forcing you to start over with a new IP. Proper warmup typically takes 4-8 weeks but pays off in long-term deliverability.