Email APIs · side by side
Customer.io vs Mailgun
Compare Customer.io, Mailgun by sending volume, delivery webhooks, inbound email, domain limits and retention.
Email APIs pricing calculator
These providers bill in different units. Each estimate uses its own workload; there is no same-volume price winner.
Customer.io
Mailgun
Customer.io
Custom / not listed
Custom / unlisted usage pricing · 25K profiles
Mailgun
$90 / mo
Scale · 100K emails
Listed USD plan fees and tracked usage only. Unlisted compute, transfer, extras, taxes and contract terms are excluded. Custom or unsupported plan usage is not estimated.
Email APIs overview & pricing
| Email APIs | Customer.io | Mailgun |
|---|---|---|
| Provider | Customer.io | Sinch |
| Billing unit | profiles | emails |
| Plan at selected usage | Custom / unlisted usage pricing | Scale |
| Monthly estimate | Custom / not listed | $90/mo |
| Workload | 25K profiles | 100K emails |
| Free access | Trial | 100 emails/day |
| Published plans | Essentials, Premium, Enterprise | Free, Basic, Foundation, Scale |
| Prices checked | 2026-10-08 | 2026-10-08 |
- Customer.io
- Customer.io
- Mailgun
- Sinch
- Customer.io
- profiles
- Mailgun
- emails
- Customer.io
- Custom / unlisted usage pricing
- Mailgun
- Scale
- Customer.io
- Custom / not listed
- Mailgun
- $90/mo
- Customer.io
- 25K profiles
- Mailgun
- 100K emails
- Customer.io
- Trial
- Mailgun
- 100 emails/day
- Customer.io
- Essentials, Premium, Enterprise
- Mailgun
- Free, Basic, Foundation, Scale
- Customer.io
- 2026-10-08
- Mailgun
- 2026-10-08
Email APIs monthly cost
Different workloads, separate estimates
Separate transactional delivery from campaigns, outreach and agent inboxes. Compare monthly sends and daily caps; contacts, seats and inboxes are not sending allowances. Budget separately for dedicated IPs, validation and attachments.
Email APIs feature comparison
| Email APIs | Customer.io | Mailgun |
|---|---|---|
| Custom sending domains | Not listed | 1,000 |
| Log retention | Not listed | 30 days |
| Message retention | Not listed | Up to 7 days |
| Inbound routes | Not listed | Full access |
| Email validations | Not listed | 5,000 included |
| SAML SSO | Not listed | |
| Phone & chat support | Not listed |
- Customer.io
- Not listed
- Mailgun
- 1,000
- Customer.io
- Not listed
- Mailgun
- 30 days
- Customer.io
- Not listed
- Mailgun
- Up to 7 days
- Customer.io
- Not listed
- Mailgun
- Full access
- Customer.io
- Not listed
- Mailgun
- 5,000 included
- Customer.io
- Not listed
- Mailgun
- Customer.io
- Not listed
- Mailgun
Which email providers fit your needs?
Customer.io features & plan notes
- Behavioral messaging
- Lifecycle workflows
- Event triggers
Mailgun features & plan notes
- Email validation
- Inbound routing
- EU region
- SAML SSO
- 5,000 email validations
- Dedicated IP pools
- 30 days log retention
- Extra emails from $1.10 / 1,000
How to compare email providers
Separate transactional delivery from campaigns, outreach and agent inboxes. Compare monthly sends and daily caps; contacts, seats and inboxes are not sending allowances. Budget separately for dedicated IPs, validation and attachments.
Browse Email APIs pricing