How are agencies using Smartlead to generate consistent SEO leads for local service businesses?

I run a small SEO agency (https://derbyseo.com) focused on local and service-based clients, and I’m testing cold email as a scalable channel.

Curious what’s actually working in 2025:
– inbox setup (domains, warm-up, volume)
– personalization depth vs scale
– reply handling → booked calls

Looking for real workflows, not theory.