Hi @Tobi Chapman 

Success of a warmup depends on 3 things -

1. Targeting most engaged audience
2. Sending best performing content to this audience
3. Monitor right KPIs and signals

Now, if engaged audience is not available (though this is the best audience to build reputation), look for other data points like:

1. Recent customers in the last 15-30 days
2. Recent validated email subscribers
3. Recent registered website users
4. Suppress blacklisted data (users who got bounced or unsubs, etc.)

Regards

Mohsin

Thank you, Mohsin. 

That’s a huge help. Really appreciate your input here. :)