Email Watchdog
Know the moment your emails bbbbbrrrrreeeeeaaaaakkkkk
Monitor every email you send. Broken links, dead images, and layout changes are caught automatically — before your customers notice.
Weekly Newsletter — Scan #14
watch-n4k8@mailchk.xyz · 2 min ago
Previous
Current
8.2%
Visual Diff
12/12
Links OK
5/6
Images OK
How It Works
Set up in 60 seconds, monitor forever
No SMTP credentials. No webhooks. No code changes. Just add an address to your list.
Create a Watchdog Address
One click gives you a unique watchdog address. Name it for the campaign or list you want to monitor.
Add to Your Mailing List
Subscribe the watchdog address in your ESP — SendGrid, Mailchimp, Postmark, or any platform. Takes 10 seconds.
Emails Are Auto-Captured
Every campaign sent to your list is automatically received, screenshotted, and checked. Links verified, images validated.
Detect Changes Instantly
Each scan is compared with the previous one. Visual diffs show exactly what changed. Broken links and dead images are flagged.
Always-On Monitoring
Every campaign, automatically checked
Your ESP sends emails normally. We catch a copy, screenshot it, check every link and image, and compare it with the last version.
Subscribe the watchdog address
Add your unique Mailchk watchdog address to your mailing list in SendGrid, Mailchimp, or any ESP. It behaves like a normal subscriber.
Campaign is sent via your ESP
When you send a campaign or trigger a transactional email, your ESP delivers a copy to the watchdog address via standard MX routing. No special configuration needed.
Automatic scan & comparison
We render the HTML in a real browser, capture a full-page screenshot, check every link and image, and pixel-diff against the previous scan. All automated, no action required from you.
Review changes in the dashboard
Every scan appears in your dashboard with a change severity score, before/after screenshots, and link + image health tables. Spot problems the moment they happen.
Your ESP / Mail Server
SendGrid, Mailchimp, Postmark, SES, SMTP...
→ sends campaign to all subscribers
Mailchk Watchdog
Your unique watchdog address
→ captured via MX routing
Mailchk Watchdog Engine
Screenshot · Link check · Image check · Visual diff
→ results available in dashboard
Your Dashboard
Before/after comparison, link & image health, change severity
No code changes required
Unlike other monitoring tools, there's nothing to install, no SMTP to configure, and no webhooks to set up. The watchdog address is a normal email subscriber — your ESP handles delivery automatically.
Use Cases
Monitor what matters
If your business sends email, Email Watchdog keeps it healthy.
Campaign Monitoring
Subscribe your weekly newsletter, product updates, and promotional campaigns. See every email as your subscribers see it — and know immediately when something breaks.
Template Regression Detection
Catch rendering regressions when your email templates change. A deployment that breaks your welcome email? You'll know within minutes, not days.
Link Rot Prevention
Links in emails break over time — pages move, domains expire, CDN URLs change. Email Watchdog catches broken links on every send so you can fix them fast.
Brand Consistency
Monitor transactional emails across your entire product. Password resets, order confirmations, welcome sequences — ensure they all stay on-brand and functional.
Features
More than just a screenshot
Visual Diff Detection
Every incoming email is screenshotted and compared pixel-by-pixel with the previous version. See exactly what changed — layout shifts, missing images, broken styling.
Link Monitoring
Every link in every email is automatically checked for a valid HTTP response. Catch broken URLs, expired tokens, and dead landing pages before your recipients click them.
Image Health Checks
All external images are verified on every scan. Know immediately when an image host goes down, a CDN link expires, or a tracking pixel breaks.
Change Severity Scoring
Changes are classified as none, minor, or major based on the visual diff percentage. Focus your attention on the emails that actually need it.
Zero Configuration
No SMTP credentials, no DNS records, no webhooks. Just add a watchdog address to your mailing list and every campaign is captured automatically.
Scan History & Trends
Full history of every email received on each watchdog address. Track changes over time and spot degradation patterns before they become problems.
One-Off Checks
Quick HTML Check
Don't need always-on monitoring? Paste your email HTML directly and get a screenshot, link validation, and image health check — instantly. No watchdog address needed.
Try Quick Check<!DOCTYPE html>
<html>
<body style="font-family: Arial">
<h1>Your order is confirmed</h1>
...
8/8
Links Valid
4/4
Images Loaded
Stop finding out from your customers
Broken images, dead links, and layout regressions happen silently. Email Watchdog catches them the moment they appear — before your subscribers notice.
FAQ