Postline — transactional email infrastructure for developers

Postline is transactional email delivery for teams: Send Email API, SPF/DKIM/DMARC, webhooks, and bounce handling on SRS-operated infrastructure.

The problem

Product teams depend on third-party email vendors: quotas, opaque deliverability, painful domain onboarding, and weak bounce control. When email is part of the product, that becomes an operating risk.

The solution

Postline is a transactional email platform for developers and teams, built around organization → project → domain → API key. It offers a Send Email API, domain verification (SPF/DKIM/DMARC), delivery webhooks, and bounce handling — self-hosted email infrastructure instead of a third-party provider.

Who it is for

Engineering and product teams that need passwords, invoices, alerts, and system mail with controlled deliverability — not a boxed marketing newsletter tool.

What the product covers

Send Email API and an organization → project → domain → key model

Domain verification: SPF, DKIM, DMARC

Delivery webhooks and bounce handling

SRS-operated infrastructure instead of resold SMTP

Talk about integration

Postline is transactional email delivery for teams: Send Email API, SPF/DKIM/DMARC, webhooks, and bounce handling on SRS-operated infrastructure.