How do you gradually reintroduce colder segments?

Prerequisites:

• Safe segment metrics stable for 2+ weeks
• Postmaster reputation improving
• No blocklist issues

Expansion process:

• Add small portion of next engagement tier
• Maybe 10-20% of current volume
• Monitor for 3-5 sends
• If stable, add more

Tiers to add:

• 60-day engagers first
• Then 90-day engagers
• 180-day engagers with extreme caution
• Never re-add truly cold segments

Warning signs to pause:

• Open rates dropping
• Complaints increasing
• Postmaster reputation declining
• Expansion is a privilege earned by stable metrics.

Gradually expand routes as trust rebuilds. Pull back immediately if problems emerge.