On the same subject, here are some tips I gleamed from Heather at SalesFolk:

One email, one focus. Send 8 different emails to every prospect. Four days apart. 30% responses come from email 5-8.

Keep it conversational, in first person.

Create benefit driven messages. How your product can help solve their problems?

Cold emails should be 2-5 sentences.

Again keep it conversational.

Keep words and sentences bare minimum.

Prove your worth. Show social proof or case study.

A/B test your message. Different value propositions. Different time/day.

Thursday Friday better than Monday.