Comparison · InboxRatio Editorial
Postmark vs SendGrid
This comparison is built from three datasets we maintain for every catalog service: documented pricing captured from the vendors' own configurators, the documented-feature matrix compiled from vendor documentation, and user ratings from G2, Capterra and Trustpilot — each value dated at its capture. Neither service has a measured deliverability score yet; we compare only what the data supports.
Editorial verdict — who fits whom
Focus versus breadth in transactional email. Postmark's Basic plan at 50,000 emails/mo is $55 against SendGrid Essentials at $19.95 (checked 2026-08-19); at the 700,000-email step — the nearest covering 500,000/mo for both — Postmark is $455/mo and SendGrid $499/mo (checked 2026-08-21). The feature dataset shows how differently they draw their boundaries: SendGrid documents 32 of our 60 tracked capabilities as included, Postmark 18 — and Postmark explicitly documents 24 capabilities as not offered, the most deliberate scope statement in this catalog (checked 2026-08-21).
Postmark fits teams that want exactly that: a sender that stays out of marketing features and says so, with per-tier pricing that undercuts SendGrid at high volume. SendGrid fits teams that want sequences, forms and a template editor beside the API, and a larger review base — 1,729 reviews to Postmark's 80 (checked 2026-08-21/22). Neither has a measured InboxRatio deliverability score yet.
Measured deliverability
Inbox placement, measured on our seed list
Postmark · tested September 2026
93/100Excellent deliverability
- Inbox96%
- Spam2.6%
- Gmail87/100
- Outlook94/100
- Yahoo96/100
SendGrid · tested September 2026
77/100Good deliverability
- Inbox88%
- Spam7.8%
- Gmail72/100
- Outlook79/100
- Yahoo82/100
Same campaign archetype, same seed composition, same measurement window for every service — how we test.
From our pricing dataset
Pricing side by side
Cheapest paid tier covering each volume, and the functional tier — the cheapest tier with automation, API access and vendor-branding removal all included — captured from the vendors' own pricing configurators on monthly billing.
| Volume | Postmark | SendGrid |
|---|---|---|
| 50,000 emails/mocheapest paid tier | $55/mo | $19.95/mo |
| 50,000 emails/mofunctional tier | $55/mo(Basic) | $19.95/mo(Essentials) |
| 500,000 emails/mocheapest paid tier | $455/mo | $499/mo |
| 500,000 emails/mofunctional tier | $455/mo(Basic) | $499/mo(Pro) |
Pricing checked 21 August 2026 · monthly billing, prices as shown by the vendor. Where a vendor has no exact step at a volume, the nearest covering step was captured (noted in the dataset).
Full pricing by volume:Postmark pricing →SendGrid pricing →
From our feature dataset
Features side by side
What each vendor documents, category by category: ✓ documented, ◐ partial or tier-gated, × documented as not offered, — not documented by the vendor. All marks reflect vendor documentation, not our testing.
| Category | Postmark | SendGrid |
|---|---|---|
| 3✓2◐1— | 6✓ | |
| Automation | 0✓2◐4× | 2✓4◐ |
| AI | 0✓1◐5× | 0✓6— |
| Personalization | 0✓2◐2× | 4✓ |
| Analytics | 1✓2◐1× | 3✓1◐ |
| Developer features | 5✓ | 5✓ |
| Marketing platform | 0✓1◐6× | 1✓1◐4×1— |
| E-commerce | 0✓5× | 0✓3×2— |
| Deliverability | 12✓5◐ | 12✓4◐1— |
Where they differ most
30 of the tracked capabilities are documented differently; the sharpest contrasts — computed from the dataset, never hand-picked:
| Capability | Postmark | SendGrid |
|---|---|---|
| Drag-and-drop editorEmail | Not documented | Documented |
| Email sequencesAutomation | Documented as not offered | Documented |
| Drip campaignsAutomation | Documented as not offered | Documented |
| SegmentationPersonalization | Documented as not offered | Documented |
| Behavioral targetingPersonalization | Documented as not offered | Documented |
| Signup formsMarketing platform | Documented as not offered | Documented |
| Blacklist monitoringDeliverability | Documented | Not documented |
| Marketing campaignsEmail | Partial / tier-gated | Documented |
| Bulk sendingEmail | Partial / tier-gated | Documented |
| Behavioral automationAutomation | Documented as not offered | Partial / tier-gated |
Features checked 10 September 2026 · from vendor documentation and official feature pages.
Independent review platforms — shown as context; never part of our measured Deliverability Score
What users say
Postmark
3.3/5
112 reviews, weightedLimited review base
- Trustpilot2.2/5 · 45 reviews
- G24.6/5 · 32 reviews
- Capterra4.7/5 · 35 reviews
Checked 10 September 2026
SendGrid
2.7/5
1,729 reviews, weightedSubstantial review base
- Trustpilot1.2/5 · 608 reviews
- G24.0/5 · 368 reviews
- Capterra4.2/5 · 753 reviews
Checked 22 August 2026
Aggregator scores diverge across platforms by design — read each platform's number with its review count; the weighted average is never shown without them.
Generated from our datasets — every value verified and dated
Frequently asked questions
Is Postmark or SendGrid cheaper at 500,000 emails/mo?
At 500,000 emails/mo, the cheapest paid Postmark tier covering that volume is $455/mo and the cheapest paid SendGrid tier is $499/mo — vendor-page prices on monthly billing, last checked 21 August 2026. Which works out cheaper for you also depends on which tier carries the features you need; the side-by-side tables above show both services' entry and functional tiers at each volume.
Do users rate Postmark or SendGrid higher?
Postmark averages 3.3/5 across 112 reviews and SendGrid averages 2.7/5 across 1,729 reviews on G2, Capterra and Trustpilot (Trustpilot counts for half of each average, checked 10 September 2026). Review-base sizes differ, so read the averages together with the counts. User ratings are context only — never part of our measured Deliverability Score.
What are the main feature differences between Postmark and SendGrid?
Of the 60 capabilities we track per vendor, Postmark and SendGrid document 30 of them differently. The comparison table above lists the headline contrasts — cells where one vendor documents a capability the other documents as absent or does not document at all. All marks reflect vendor documentation, not our testing.
Has InboxRatio tested Postmark and SendGrid's deliverability?
Postmark has a published seed-list placement test dated 1 September 2026. SendGrid has a published seed-list placement test dated 5 September 2026. The table above shows both services' measured inbox placement and Deliverability Scores. How we test.
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