Postmark

Postmark deliberately limits itself to transactional email. Streams keep transactional and broadcast traffic separated. The product emphasizes message activity retention, clear debugging, and volume pricing with no feature gates.

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, Postmark covers multi-tenant support, event stream, the suppressions API, and webhook coverage, and does not cover operating track record, scheduling, and best published rate per 1,000. Whether that gap matters depends on how central those are to the build.

• Multi-tenant: Yes
• Event stream: Yes
• Suppressions API: Yes
• Operating since: 2010
• Scheduling: No
• Best published rate per 1,000: $1.50
• Deliverability: Strong transactional reputation with separate streams for transactional and broadcast traffic, which helps protect sender reputation.
• Webhooks: Yes
• Starts at: $15/mo for 10,000 emails

Strong transactional reputation with separate streams for transactional and broadcast traffic, which helps protect sender reputation.

Teams where password resets, receipts, and magic links absolutely cannot miss the inbox.

Marketing automation, abandoned-cart sequences, lifecycle nurturing.