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Deliverability Hegemony & Analytics Integrity

In-Flight Bot-Click Defense & Magic Link Shield

Corporate security scanners click email links within milliseconds of arrival, inflating CTR by up to 800% and prematurely burning single-use magic links. SadaSend transparently classifies automated crawler probes in sub-10ms without slowing down human browsing.

< 10ms
Redirect Latency
0
Prematurely Burned Tokens
100%
Verified Human CTR
$0
Extra Add-On Cost

Interactive Bot-Click Classifier

Select a security crawler or legitimate visitor to test the sub-10ms classification engine.

Sub-10ms Redirecttrack.sadasend.com
Classification
Automated Crawler
Gateway Action
CTR Suppressed
Redirect Latency
6 msZero lag
Scanner Confidence
98%heuristic
Inbound Request Probe
GET /t/c/msg_8849b2
User-Agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36 (compatible; ms-office; MSOffice 16)
Request Headers:
Purpose:prefetch
X-MS-Exchange-Organization-AuthAs:Anonymous
Sec-Purpose:prefetch;prerender
Destination Target:
https://example.com/verify-account?token=auth_9a2f1b
Gateway Classifier Payload
JSON
{
  "ok": true,
  "status": 302,
  "redirectLocation": "https://example.com/verify-account?token=auth_9a2f1b",
  "trackingEvent": {
    "id": "clk_defender-safelinks_9021",
    "timestamp": "2026-11-09T16:31:47.160Z",
    "is_bot": true,
    "classification": "microsoft_defender_safelinks",
    "threat_category": "automated_security_prefetch",
    "risk_score": 98,
    "action_taken": "suppress"
  },
  "performanceMetrics": {
    "redirect_latency_ms": 6,
    "classification_pipeline": "in_flight_asynchronous",
    "edge_node": "sadasend_edge_frankfurt"
  },
  "analyticsImpact": {
    "human_ctr_recorded": false,
    "webhook_fired": "security.bot_probe_suppressed",
    "token_consumed": false,
    "note": "Probe excluded from customer CTR analytics"
  }
}
Classification Rationale & Customer Protection

Detected Microsoft Defender asynchronous link prefetch probe. Returned a neutral 200 HTTP response, prevented premature token consumption, and excluded the probe from human CTR metrics.

Core Architecture

Four Layers of In-Flight Click Protection

Engineered into our native edge router to deliver authentic human engagement metrics without impacting deliverability.

< 10ms Latency

Sub-10ms Asynchronous Classification

Tracking redirects execute instantly on track.sadasend.com while request entropy, HTTP headers, and IP heuristics are evaluated in-flight without adding user friction.

Technical invariant: Zero-delay redirect pipeline: human recipients are forwarded in sub-10ms while classification completes concurrently in the edge worker background.
Zero Burned Logins

Single-Use Auth & Token Deferral

Security bots frequently fetch authentication links before recipients open their email, burning one-time tokens. SadaSend defers token consumption until authentic human interaction.

Technical invariant: Prefetch headers (Purpose: prefetch, X-Purpose: preview) and scanner user-agents receive a neutral holding response, preserving the token for the human recipient.
is_bot: true/false

Webhook Stream Tagging & DLQ

Webhook events explicitly differentiate between authentic human interaction and security crawler probes, keeping downstream CRM and analytics pipelines 100% clean.

Technical invariant: Dispatches email.clicked payloads with detailed bot classification metadata (scanner_family, bot_score, confidence) so automations never fire accidentally.
100% Real CTR

Investor-Grade Human CTR Metrics

Eliminate 400% to 800% vanity metric inflation caused by corporate security appliances scanning every inbound message across your customer base.

Technical invariant: Separates aggregate scanner traffic from verified human sessions, giving product teams and investors authentic engagement figures.
Battlecard

SadaSend vs Legacy Transactional Mailers

Legacy mailers count automated bot probes as legitimate clicks, forcing companies to build custom heuristic scripts.

ProviderBot Filtering PipelineSingle-Use Token ShieldRedirect LatencyWebhook PayloadVerdict
SadaSendNative in-flight classifier (< 10ms)Included ($0 floor, token deferral)Sub-10ms transparent forwardExplicit is_bot: true / falseBuilt-In
SendGridNone (all crawler probes counted)None (crawlers burn tokens)45ms - 120ms legacy proxyNo bot metadata in webhooksVulnerable
ResendBasic IP blocklist onlyNone (burns magic links)25ms - 60ms cloud wrapperNo scanner classificationVulnerable
PostmarkBasic known user-agent regexManual custom code required20ms - 40msPartial metadata on select tiersVulnerable
Developer Integration

Filter Scanners in 3 Lines of Code

Listen to the verified email.clicked webhook and inspect the is_bot boolean.

Listen to verified click webhooks and filter bot traffic with strict typing.

TYPESCRIPT
import { createHmac, timingSafeEqual } from 'node:crypto';
import type { Request, Response } from 'express';

interface ClickEvent {
  event: 'email.clicked';
  id: string;
  recipient: string;
  url: string;
  is_bot: boolean;
  bot_classification?: {
    scanner_family: string;
    confidence: number;
    action_taken: 'suppressed' | 'deferred' | 'recorded';
  };
  timestamp: string;
}

export function handleEmailWebhook(req: Request, res: Response) {
  const payload = req.body as ClickEvent;

  if (payload.event === 'email.clicked') {
    if (payload.is_bot) {
      // Automated scanner detected: do NOT trigger user automations
      console.log(`[Bot Probe Suppressed] ${payload.bot_classification?.scanner_family} on ${payload.url}`);
      return res.status(200).json({ status: 'bot_probe_acknowledged' });
    }

    // Authentic human click: safe to trigger onboarding workflows
    console.log(`[Verified Human Click] ${payload.recipient} clicked ${payload.url}`);
    triggerCustomerWelcomeSequence(payload.recipient);
  }

  return res.status(200).json({ ok: true });
}
FAQ

Frequently Asked Questions

Restore True CTR & Protect Your Magic Links

Included out-of-the-box in SadaSend Pro ($19/mo) and Scale plans with zero extra configuration. Stop letting corporate scanners corrupt your product analytics.