By starting 15+ years ago, when this was marginally easier, and there was far less competition. Mailchip is 20. Campaign Monitor is 17 (and have been buying up

By starting 15+ years ago, when this was marginally easier, and there was far less competition. Mailchip is 20. Campaign Monitor is 17 (and have been buying up other email related companies/brands for years). SendGrid is about 12. Mailgun is 11. There's a lot of competition out there, and it's not easy to overcome all the blocklist challenges - paying customers aren't willing for you to experiment with their customer's getting their email.