Email Service Provider (ESP)
The platform that sends your marketing email — Mailchimp, Klaviyo, ConvertKit, and kin. Handles lists, templates, automation, and compliance plumbing.
Free · no signup · last reviewed August 29, 2026
The definition
The platform that sends your marketing email — Mailchimp, Klaviyo, ConvertKit, and kin. Handles lists, templates, automation, and compliance plumbing.
Why it matters to an owner
Pick for exportability as much as features: your list must leave with you in one click. An ESP that makes export hard is holding your audience hostage.
Keep going
This is the work. Want it done?
Everything here is free to use yourself — that’s the point. If you’d rather a senior marketer just handle it, in your accounts and your name: 20-minute call, no pitch deck.