A small, sending-only service against the largest name in the category. They differ on whether there is a free tier at all, on what $15 to $20 a month buys, and on which plan carries validation tooling and a written SLA. This page reads both pricing pages and puts the figures side by side; Notix appears as a third column, not as the subject.
Postmark's figures were read from its pricing page on 2026-09-13 and SendGrid's from its pricing page on 2026-09-13; both dates are repeated under the table. Notix figures come from its own pricing page.
| Criterion | Postmark | SendGrid | Notix |
|---|---|---|---|
| Free tier | 100 emails a month on the developer plan | 60-day trial, 100 a day; sending stops when the trial ends (the free plan was retired from 27 May 2025) | 5,000 emails a month, 200 a day, no card, no end date |
| Entry paid plan | Basic $15 a month | Essentials from $19.95 a month | Pro $15 a month |
| Included on that plan | 10,000 emails a month, then $1.80 per extra 1,000 | 50,000 to 100,000 emails a month on Essentials, volume-priced | 50,000 emails, usage past that metered on the same invoice |
| SMTP relay | Yes, on every plan | Yes | Yes, on every plan |
| SDKs | Node, Python, Ruby, PHP, .NET, and a documented cURL surface | Node, Python, PHP, Ruby, Go, Java, C# | TypeScript, Python, Go, PHP |
| Webhooks | Yes | Yes | Yes, signed, for email, contact and domain events |
| OTP / verification API | No | No | Yes, email and SMS codes |
| Deliverability check before sending | No | Email validation API on Pro and above | Yes, a pre-send check API |
| Billing outside USD | USD by card | USD by card | USD by card; naira and shillings from a prepaid wallet |
| SLA | Not stated on the pricing page | Stated for Pro and Premier plans | 99.9% on Pro, credits on the pricing page |
| Prices and limits read from the vendors' own pages: postmarkapp.com on 2026-09-13; www.twilio.com on 2026-09-13. Notix figures are from its own pricing page. | |||
Postmark's developer plan is 100 emails a month with no end date. SendGrid retired its free plan from 27 May 2025; a new account now gets a 60-day trial at 100 emails a day, after which sending stops. Neither is enough to run a product on, but they behave differently: Postmark's stays useful for a test integration indefinitely, SendGrid's ends and asks for a card.
Postmark Basic is $15 a month for 10,000 emails, then $1.80 for each extra 1,000. SendGrid Essentials starts at $19.95 a month and is sized for 50,000 to 100,000, volume-priced. At 10,000 emails Postmark is about $5 cheaper; at 50,000 Postmark Basic reaches about $87 against SendGrid's $19.95, unless you move up a Postmark plan. The lines cross a little under 13,000 emails a month.
Both take a JSON body with from, to, subject and html and return a message id, and both offer SMTP, so a framework mailer or a legacy application can send without the API. A plain transactional send moves between the two after a client swap and a credential change; neither locks you in at the send call. Where they differ is around the send, not in it.
SendGrid lists Node, Python, PHP, Ruby, Go, Java and C#. Postmark lists Node, Python, Ruby, PHP and .NET, with a documented cURL surface for everything else. Node, Python, PHP and Ruby teams get a typed client from both; Go and Java teams get one from SendGrid only. For the languages both cover, the clients are the same shape and the choice will not rest on them.
Both deliver event webhooks for delivery, bounce and complaint events, so a bounced address can be marked in your own database. SendGrid offers an email validation API on Pro and above; Postmark's pricing page lists no validation product. Neither offers a one-time-code API, and neither offers a deliverability check you can call before a send.
Both bill in US dollars by card. SendGrid states an SLA for its Pro and Premier plans; Postmark's pricing page does not state an SLA figure. Neither entry plan carries a written uptime commitment. If one is a requirement, SendGrid's Pro plan meets it and Postmark's pricing page, as read here, does not say.
On the same criteria: Notix Free is 5,000 emails a month and 200 a day with no card and no end date, which is more than Postmark's developer plan and, unlike SendGrid's trial, does not expire. Pro is $15 a month for 50,000 emails, with usage past that metered on the same invoice, which undercuts both paid plans at 50,000. SMTP, webhooks and SDKs for TypeScript, Python, Go and PHP are on every plan. The rows where it differs are the ones the entry plans of both headline services leave empty: a verification API for one-time codes by email or SMS, a deliverability check you call before a send, a 99.9 percent commitment on the $15 plan, and billing from a naira or shilling wallet as well as by card.
Five times the included volume at the same $15, with the marketing side and an OTP API in the same account.
AlternativesA free plan that does not end after 60 days, a suppression import, and an API you can move to in an afternoon.
CompareTen thousand emails for $15 against fifty thousand, and the one thing Postmark has that Notix does not claim.
CompareWhat changes when you leave a 60-day trial for a free plan that stays, and where SendGrid's scale still wins.
CompareEvery vendor in one table with read dates, and a straight answer to which transactional email API a startup should pick.
NotixA free plan with no card, and Pro at $15 a month for 50,000 emails. Only sent volume is metered.
5,000 emails a month on Free, no card, no end date. Pro is $15 for 50,000 emails.