Mailgun vs Fly.io
Email API for developers with deep deliverability tooling
vs. Run your app close to users, globally
Pricing tiers
Mailgun
Free
100 emails/day. 1 custom domain, 1-day log retention, 1 inbound route. No credit card.
Free
Basic
$15/month. 10,000 emails/month, no daily limit, 5 inbound routes.
$15/mo
Foundation
$35/month (1st month free). 50,000 emails/month, 1,000 custom domains, 5-day retention.
$35/mo
Scale
$90/month. 100,000 emails/month, SAML SSO, 5,000 email validations, dedicated IP pools, 30-day retention.
$90/mo
Enterprise
Custom. Deliverability services, managed onboarding.
Custom
Fly.io
Pay-as-you-go
No monthly fee. Machines billed per second. Free allocations: ~3 small shared machines + 3 GB volumes.
$0 base (usage-based)
Shared CPU 1x — 256 MB
Entry VM. 1 shared vCPU, 256 MB RAM. ~$2.02/month continuously on.
$2/mo
Performance 1x — 2 GB
Dedicated 1 vCPU, 2 GB RAM.
$32/mo
Reservation — Shared (1 yr)
$36/year for $5/mo credit (40% savings).
$36/mo
Shared CPU 8x — 16 GB
8 shared vCPU, 16 GB RAM.
$89/mo
Performance 16x — 128 GB
Dedicated 16 vCPU, 128 GB RAM.
$1014/mo
Enterprise
Custom. Dedicated capacity, SLA.
Custom
Free-tier quotas head-to-head
Comparing free on Mailgun vs pay-as-you-go on Fly.io.
| Metric | Mailgun | Fly.io |
|---|---|---|
| No overlapping quota metrics for these tiers. | ||
Features
Mailgun · 14 features
- Batch Sending — Send up to 1,000 recipients per API call via recipient variables.
- Dedicated IPs — IP pools with auto warmup. Scale+ tier.
- Deliverability Suite — Inbox placement testing, DMARC reporting, seed lists.
- Email Logs — Searchable log of all send attempts + events.
- Email Templates — Template builder + variables + versioning.
- Email Validation — Real-time email verification (syntax, MX, role accounts, disposable).
- EU Region — Data stored in EU for GDPR-sensitive customers.
- Inbound Routing — Route incoming emails to URLs/SMTP. Attachment forwarding.
- Mailing Lists — Unlimited mailing lists with bulk subscribe/unsubscribe.
- Open/Click Tracking — HTML + text tracking with configurable tracking domain.
- SAML SSO — Scale+ tier.
- Send API — REST/SMTP send with MIME + tracking.
- Tags — Tag messages to slice stats.
- Webhook Events — delivered, opened, clicked, unsubscribed, complained, permanent_fail, temporary_…
Fly.io · 14 features
- Auto Stop/Start — Machines auto-stop when idle, start on request (like scale-to-zero).
- Certs — Let's Encrypt + wildcard certs managed.
- Fly GPU — A100/L40S/A10 on-demand GPU machines.
- Fly Kubernetes (FKS) — Managed Kubernetes on Fly machines.
- Fly Machines — Firecracker microVMs. Start in <1s. Run any Docker image.
- Fly Postgres — Managed Postgres via Supabase partnership (2024). Also legacy self-run Postgres …
- fly-replay headers — Route request to another region at app level.
- Fly Volumes — Persistent SSD attached to a Machine. Encrypted at rest.
- Global Anycast — Single IP routes to the closest region automatically.
- LiteFS — Distributed SQLite with primary/replica across regions.
- Private Networks — 6PN WireGuard mesh. Connect machines across regions privately.
- Secrets — Encrypted env vars propagated to all regions.
- Tigris (partner) — S3-compatible storage for Fly apps. By partner.
- Upstash Redis (partner) — Managed Redis via Upstash.
Developer interfaces
| Kind | Mailgun | Fly.io |
|---|---|---|
| CLI | — | flyctl CLI |
| SDK | mailgun.js (Node), mailgun-php, mailgun-python, mailgun-ruby | — |
| REST | Mailgun REST API | Machines API |
| GRAPHQL | — | Fly GraphQL API |
| OTHER | Inbound Routing, SMTP Relay, Webhooks | Fly Postgres (wire) |
Staxly is an independent catalog of developer platforms. Some links to Mailgun and Fly.io may be affiliate links — Staxly may earn a commission if you sign up through them, at no extra cost to you. Pricing is verified against vendor pages at publication time — reconfirm before buying.
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