Mailgun vs Flagsmith
Email API for developers with deep deliverability tooling
vs. Open-source feature flags + remote config — SaaS, private cloud, self-host
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
Flagsmith
Free
$0. 50,000 API requests/mo. 1 team member. Unlimited flags. Community support.
Free
Self-hosted
$0 (OSS). Host yourself via Docker/K8s. Fair-source license (non-compete).
$0 base (usage-based)
Start-up
$40/mo. 1,000,000 API requests/mo. 3 team members. Standard support.
$40/mo
Scale-up
$200/mo. 5,000,000 API requests. 10 team members. Priority support + SLA.
$200/mo
Enterprise
Custom. Unlimited API requests, SSO, SAML, RBAC, audit logs, on-prem.
Custom
Free-tier quotas head-to-head
Comparing free on Mailgun vs free on Flagsmith.
| Metric | Mailgun | Flagsmith |
|---|---|---|
| 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_…
Flagsmith · 14 features
- A/B Testing — Multivariate flag splits.
- Audit Log — Full history of flag changes.
- Change Requests — Approval workflow for flag changes.
- Edge API — Global low-latency flag eval.
- Feature Flags — Boolean + multivariate + JSON flags.
- Local Evaluation — Server SDKs eval flags locally — no per-req API call.
- Percentage Rollouts — Gradual traffic ramp.
- Remote Config — Non-boolean config values.
- Role-Based Access — Fine-grained permissions.
- Scheduled Flags — Time-based flag changes.
- Segments — Rule-based targeting.
- Self-Hosting — Docker/Helm install.
- SSO + SAML — Enterprise SSO.
- Webhooks — Outbound event streaming.
Developer interfaces
| Kind | Mailgun | Flagsmith |
|---|---|---|
| CLI | — | Flagsmith CLI |
| SDK | mailgun.js (Node), mailgun-php, mailgun-python, mailgun-ruby | flagsmith-android, flagsmith-go, flagsmith-ios, flagsmith-java, flagsmith-js (browser), flagsmith-nodejs, flagsmith-python, flagsmith-ruby |
| REST | Mailgun REST API | Flagsmith REST API |
| OTHER | Inbound Routing, SMTP Relay, Webhooks | Flagsmith Dashboard, Flagsmith Webhooks |
Staxly is an independent catalog of developer platforms. Some links to Mailgun and Flagsmith 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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