Connecting your email platform
Which platforms work, and what each connection is used for.
Updated October 3, 2026 · 1 min read
Go to Settings → Newsletter & ESP and choose your platform. We support beehiiv, Kit, Mailchimp, MailerLite, ActiveCampaign, Klaviyo and Brevo. Using another platform? Choose “My platform isn't listed” to ask for it.
dash.subswell.app/settings
Newsletter & ESP
Email platform
beehiivPublication ID
pub_8f2c…
API key
••••••••••••••••••••
Update & verify Connected · 12,480 subscribers
What the connection is used for
- Advertisers: new subscribers are added straight to your list, and we check during the quality check that they're still subscribed.
- Publishers: we read your list size and sending stats for your review, and check that readers you refer really signed up to your newsletter.
API key permissions
- beehiiv: a key with subscription read/write access. Add custom field read/write too, so we can label the readers we send you.
- Klaviyo: a private key with profiles, lists, events and subscriptions access.
Is Substack supported?
Not at the moment. Substack has no API, so we can't check that the readers we send are real and still subscribed, which is what advertisers pay for. If Substack opens an API, we'll add it.