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IP Warm-Up for New Sending IPs — The Right Way

Cold IPs have no history — receivers assume worst. Volume spikes look like botnets. Warm-up is proving you are boring and legitimate.

Pattern

Day 1-3: seed inboxes + real engaged users. Ramp slowly. If metrics wobble, hold steady — do not “catch up” with a blast.

Related: email deliverability and blacklisted IP.

FAQ

How long does warm-up take?

Often 2-4 weeks to stable reputation — varies by volume and list quality.

What volume day one?

Start tiny — tens to low hundreds — double only when bounces and complaints stay low.

Does dedicated IP matter for ESPs?

ESP shared pools already have reputation — dedicated IPs start cold.

What metrics watch?

Bounce rate, spam complaints, deferrals — stop ramping if they spike.

PTR required?

Yes for SMTP IPs — align with <a href="/blog/ptr-record-email-delivery/">PTR guidance</a>.