SaaS & Technology

Deliverability data
for data people.

Your team doesn't want dashboards that hide the details. You want to see the raw deferral codes, understand why Gmail is throttling you, and query the data yourself. You want technical depth, not marketing fluff.

Finally, email intelligence built for engineers.

DEFERRAL INTELLIGENCE SMTP Response Analysis 421 (65%) 450 (25%) 452 (10%) 421-4.7.0 Try again later. gmail-smtp-in.l.google.com ISP PERFORMANCE ISP Delivery Deferral Bounce Gmail 98.2% 4.1% 1.2% Microsoft 97.8% 2.3% 1.8% Yahoo 96.5% 1.9% 2.1% Apple 99.1% 0.8% 0.6% COHORT ENGAGEMENT DECAY W0 W1 W2 W3 W4 W5 TREND Dec 2025 42% 38% 35% 32% 29% -1.2%/wk Nov 2025 45% 41% 38% 34% 31% -0.9%/wk BOUNCE CLASSIFICATION Hard Bounces (550) 1.2% Soft Bounces (4xx) 0.8% Unknown 0.1% API ACCESS GET /api/v1/metrics Authorization: Bearer sk_... {"delivery_rate": 97.8, "deferral_rate": 2.1}
The Technical Reality

You need more than pretty charts

ESP dashboards hide the details

"Delivery rate: 97%" — but what happened to the other 3%? Soft bounce? Hard bounce? Throttled? Blocked? You need to see the SMTP codes, not just the summary.

No visibility into throttling patterns

Gmail is deferring your emails, but is it volume-based? Reputation-based? Time-of-day? Without the raw data, you're guessing at solutions.

Engagement decay is a black box

Users stop engaging, but when? Which cohort? How fast? You can't optimize onboarding or re-engagement without cohort-level visibility.

The Engagor Approach

Technical depth without the data engineering

01

Deferral intelligence with SMTP context

See every deferral code: 421, 450, 452. Understand if it's throttling, reputation, or rate limiting. Track patterns by ISP and time of day.

Deliverability Analytics ->
02

ISP-by-ISP breakdown

Gmail treats you differently than Microsoft. See delivery rates, deferral patterns, and engagement metrics broken down by provider.

ISP Performance ->
03

Cohort engagement analysis

Track how engagement decays over time by signup cohort. Compare December signups to November. See exactly when users disengage.

Cohorts & Segments ->
04

Bounce classification that matters

Hard vs soft isn't enough. See the actual bounce codes, understand the root cause, distinguish list hygiene from reputation problems.

Bounce Intelligence ->

Deliverability data for data people

See how Engagor gives technical teams the depth they need.