Service Level Agreement
Last updated: 2026-05-07
1. Scope
This Service Level Agreement (“SLA”) applies to Scale and Enterprise plan customers and defines our uptime and performance commitments.
2. Uptime Commitment
| Metric | Target |
|---|---|
| API availability | 99.9% monthly |
| SMTP relay availability | 99.9% monthly |
| Dashboard availability | 99.9% monthly |
3. Performance Targets
| Metric | Target |
|---|---|
| Production API P95 (gateway) | ≤500ms |
| Email acceptance to first delivery attempt | ≤30 seconds |
| Webhook delivery (P95) | ≤5 seconds |
Metric Definitions
Production API P95 (gateway): Measured at the API gateway layer for all production POST /v1/messages requests. Start timestamp: request ingress at gateway. End timestamp: response egress from gateway. Percentile: P95. Qualifying requests: HTTP 200-299 responses from the messages endpoint, excluding sandbox/test API key traffic. Exclusions: health-check probes, preflight OPTIONS, sandbox API keys. Sample period: trailing 30-day window, 1-minute aggregation buckets.
4. Measurement
Uptime is measured by our external monitoring system (Blackbox exporter + Prometheus) from multiple geographic locations. Scheduled maintenance windows (announced 48 hours in advance) are excluded.
5. Service Credits
| Plan | Availability commitment | Monthly credit cap |
|---|---|---|
| Scale | 99.9% | 10% |
| Enterprise | 99.9% | 25% |
Credits are calculated from measured monthly uptime below the commitment and capped by the customer’s plan.
6. Exclusions
Credits do not apply to: force majeure, customer-caused issues, scheduled maintenance, or beta features.
7. Claiming Credits
Submit credit requests to support@apexmail.ee within 30 days of the incident. Credits are applied to the next billing cycle.