Substack
Hosted newsletter platform with social network features.
Substack is closed and opinionated: 10% revenue cut, no API, no custom domains for free, but distribution and recommendations are real. Largely outside the developer toolchain conversation.
A SaaS product sends on behalf of its customers, so the deciding factors are tenant isolation, whether suppressions can be scoped rather than global, and whether support can answer why one specific account did not receive one specific email. Lifecycle automation and transactional sending usually need to coexist.
Against trial expiry notices, dunning, onboarding sequences, and per-tenant transactional mail, Substack covers the suppressions API and scheduling, and does not cover multi-tenant support, event stream, operating track record, and webhook coverage. Whether that gap matters depends on how central those are to the build.
- Multi-tenant: No
- Event stream: No
- Suppressions API: Yes
- Operating since: 2017
- Scheduling: Yes
- Best published rate per 1,000: Tiers not published in comparable form
- Deliverability: Reasonable for content-driven newsletters.
- Webhooks: No
- Starts at: 10% revenue cut
Reasonable for content-driven newsletters.
Writers who prioritize distribution over flexibility.
- › Distribution via the Substack network
- › No platform fees beyond revenue cut
- › No API, no automation, no custom domain on free
- › Lock-in to platform
Features at a glance
| API | No |
| SMTP | No |
| SDKs | None |
| Webhooks | No |
| Templates | basic |
| React Email | No |
| Batch send | Yes |
| Scheduled send | Yes |
| Suppressions | Yes |
| Multi-tenant | No |
| Inbound parsing | No |
| Event stream | No |
| Idempotency keys | No |
| Dedicated IP | No |