StableEmail

Communication

Pay-per-send email delivery.

96.9
out of 100

High accuracy (93%) — responses consistently matched expected behavior. Very reliable — 10/10 requests got a response. Median response time: 1382ms (p95: 2122ms).

Last tested: 3/19/2026, 5:51:05 PM

What AI models say

GPT-4o-mini

“Nine out of ten API requests succeeded, with high-quality responses and a moderate average response time.”

Haiku

“Nine of ten requests succeeded with 93% quality and 1.35-second response times.”

Accuracy (40%)
93.0
Reliability (30%)
100.0
Latency (20%)
98.7
Cost Efficiency (10%)
100.0

Test Examples

Real requests we sent and the responses we received.

Test sending an email with a follow-up message.

POST /api/sendtypical1590ms
100%

{"from":"\"StableEmail\" <relay@stableemail.dev>","success":true,"messageId":"0100019d0738e807-81c2aa52-fcf7-45f6-b422-c2608bd8e473-000000"}

Test sending an email with very short content.

POST /api/sendedge1367ms
100%

{"from":"\"StableEmail\" <relay@stableemail.dev>","success":true,"messageId":"0100019d0738b655-a1b8e552-e2e2-4997-ad18-fcde7b4ad3f4-000000"}

Test sending an email with a friendly greeting.

POST /api/sendtypical1425ms
100%

{"from":"\"StableEmail\" <relay@stableemail.dev>","success":true,"messageId":"0100019d0738cef5-e0038fde-6e3d-44a2-a112-2a17c03c72bc-000000"}

Test sending an email with an empty content string.

POST /api/sendadversarial383ms
30%

HTTP 400

Service Details

Endpoint: https://stableemail.dev
Status: active
Discovered: 3/18/2026
Tests run: 10
Last tested: 3/19/2026

Test History

3/19/2026, 5:50:47 PM
score: 93%p50: 1382ms
3/19/2026, 4:30:34 PM
score: 93%p50: 1399ms
3/19/2026, 3:59:58 PM
score: 93%p50: 1315ms
3/19/2026, 12:31:15 AM
score: 93%p50: 1449ms

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How do we test? Read our methodology.