Postmark vs Helicone
Reliable transactional email with fast delivery
vs. Open-source LLM observability — 1-line integration via proxy
Pricing tiers
Postmark
Free
100 emails/month forever. No credit card. Side projects and testing.
Free
Basic — 10k
10,000 emails/month. Overage $1.80/1k. Unlimited emails/day.
$15/mo
Pro — 10k
10,000 emails/month. Overage $1.30/1k. Inbound email + message streams.
$17/mo
Platform — 10k
10,000 emails/month. Overage $1.20/1k. Team collab, more domains.
$18/mo
Enterprise (>1.5M)
Custom for senders exceeding 1.5M/month.
Custom
Helicone
Hobby (Free)
10,000 requests/month. 7-day retention. 1 seat. Basic monitoring.
Free
Startup Discount
<2 years, <$5M funding: 50% off first year.
$0 base (usage-based)
Self-Hosted (OSS)
MIT-licensed. Run Helicone yourself for free.
$0 base (usage-based)
Pro
$79/month. 10k free + usage-based. Unlimited seats. Alerts, reports, HQL query language. 1-month retention.
$79/mo
Team
$799/month. 5 orgs, SOC-2 + HIPAA compliance, dedicated Slack, 3-month retention.
$799/mo
Enterprise
Custom MSA, SAML SSO, on-prem deploy, bulk discounts, forever retention.
Custom
Free-tier quotas head-to-head
Comparing free on Postmark vs hobby on Helicone.
| Metric | Postmark | Helicone |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
Postmark · 12 features
- Activity Search — Full-text search over sent messages for 45-365 days.
- Bounce Handling — Automatic hard/soft bounce detection + suppression management.
- Broadcast Messages — Via separate Broadcast Message Stream. Bulk sends with throttling.
- DKIM + SPF — One-click verification + auto-renewal of DKIM keys.
- Inbound Email — Route inbound emails to your webhook. Parse attachments, threads.
- Message Streams — Isolate transactional from marketing for separate deliverability reputation.
- Open + Click Tracking — Configurable at template or send level.
- Raw API Access — 100+ endpoints for bounces, servers, tags, templates, stats.
- Servers — Multi-tenant isolation: each "server" has its own API token + reputation.
- Templates — Mustachio template language with variables, alias + versioning.
- Transactional Send — Reliable API for password resets, receipts, notifications. Sub-10s delivery.
- Webhook Events — Delivery, bounce, spam complaint, open, click, subscription change.
Helicone · 16 features
- Alerts — Thresholds on error rate, latency, cost, usage. Pro+.
- Async Logging — Log AFTER the LLM call via SDK — zero added latency.
- Cost Tracking — Automatic cost calculation per call by provider/model.
- Dashboard — Request tables, aggregate metrics, cost breakdowns.
- Evaluators — LLM-as-judge + custom evaluators on runs.
- Experiments — A/B test different models/prompts.
- HQL (SQL over traces) — Query your logged data with SQL. Pro+.
- PII Redaction — Automatically scrub emails, credit cards, etc. from logs.
- Prompt Caching — Cache identical requests → save money.
- Prompts & Versions — Store + version + A/B test prompts.
- Proxy Mode — 1-line integration via base URL swap. Captures all requests.
- Rate Limiting — Per-user + per-key rate limit policies.
- Reports — Scheduled email reports with KPIs.
- Self-Hosting — Docker + k8s deployment.
- Sessions — Group related calls (chat sessions, agent runs).
- User Metrics — Per-user cost + usage segmentation.
Developer interfaces
| Kind | Postmark | Helicone |
|---|---|---|
| CLI | — | Helicone CLI |
| SDK | postmark-dotnet, postmarker (Python), postmark-go, postmark (Node), postmark-php, postmark-rails | helicone (npm), helicone-python |
| REST | Postmark REST API | Async Logging API, Helicone Proxy, Query API (HQL) |
| OTHER | Inbound Email, SMTP Relay, Webhooks | Helicone Dashboard, Webhooks |
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