What’s the difference between permission and engagement-based warmup?

Permission-based warmup and engagement-based warmup represent different approaches to building sender reputation and list quality.

Permission-based warmup:

Uses contacts who explicitly opted in to receive email

Starts with best possible engagement foundation

Consent is documented and defensible

Lower risk of complaints

Appropriate for marketing email programs

Engagement-based warmup:

Uses contacts based on behavioral signals (opens, clicks, replies)

May include contacts who engaged but didn't explicitly opt in

Assumes engagement implies interest

Higher risk profile for marketing transition

More appropriate for continuing sales conversations

The distinction matters because:

Engagement isn't consent under many regulations

People may engage with cold email but not want marketing

Mixing engagement with permission creates compliance ambiguity

Marketing lists should be permission-based

Appropriate use cases:

Engagement-based: Continuing sales outreach to engaged prospects

Permission-based: Transitioning contacts to marketing lists

The type of warmup should match the intended use of the list.