SendLayer

SendLayer is a transactional sender focused on API and SMTP relay, domain authentication, logs, suppression management, bounce handling, blocklist monitoring, event webhooks, and analytics. Plans are simple but billed annually, and the entry plan is small at 1,000 emails per month.

Judged purely as an API. What the request contract guarantees on retry, how complete the webhook event coverage is, whether suppressions are readable and writable programmatically, and how much the message log retains when something needs debugging in production.

Against high-frequency programmatic sends where a missed delivery is a product failure, SendLayer covers webhook coverage, event stream, the suppressions API, and batch sending, and does not cover idempotency keys and SDK breadth. Whether that gap matters depends on how central those are to the build.

• Idempotency keys: No
• Webhooks: Yes
• Event stream: Yes
• Operating since: Not published
• Suppressions API: Yes
• Best published rate per 1,000: Tiers not published in comparable form
• Batch sending: Yes
• SDKs: None
• Deliverability: Transactional sender with authentication, active anti-spam, bounce handling, blocklist monitoring, and event-based webhooks. Public independent deliverability history is thinner than Postmark or SMTP2GO.

Transactional sender with authentication, active anti-spam, bounce handling, blocklist monitoring, and event-based webhooks. Public independent deliverability history is thinner than Postmark or SMTP2GO.

Small WordPress, app, or SaaS projects that need simple transactional delivery at low volume.

Teams that want monthly billing or large free-tier volume.