Cold emailing local businesses - what is working in 2026?

Hey Indie Hackers,

I'm building ReviewLift, a review funnel tool for UK plumbers, barbers, cafes - local service businesses that are not tech native.

My current approach has been:

• Hyper personalised: I mention their exact Google review count, compliment a recent award, and show a custom demo link with their business name already in the funnel.

• Low volume: I send 25–50/day max. Opens are solid though (around 42%).

The problem: Sign ups are slow, painfully slow (1 so far).

My dilemma:
I could 10x my volume with semi-personalised templates—just business name with a generic demo. But I'm worried I'll lose the magic that gets me 42% opens and engagement.

For those targeting non-tech owners:

• Did you find a middle ground between "Dear Sir/Madam" and "I know everything about you"?
• Is a 42% open rate actually good enough to justify the time spent personalising?
• Did you ever switch to volume, and did it kill your brand perception?

Appreciate any feedback.