Email tracker for Gmail
Know when your emails are opened. WhatsApp-style checkmarks and real-time notifications, right inside Gmail.
Watch the whole flow, from install to the first blue checks:
How it works
WhatsApp-style checkmarks
One gray check when sent. Double blue checks when opened. Visual status appears right next to each email in your inbox, just like WhatsApp.
Real-time desktop notifications
Get a Chrome notification the moment someone opens your email. Works even when Gmail is not open. Click the notification to jump straight to that email.
Smart notification types
Four categories: First Open (within 7 days), Cold Revival (first open after 7+ days), Re-engagement (re-opened after 24h+), and Old Email Reopened (30+ days). Enable only the ones you care about.
Toggle per email
Click the read receipt button in the compose toolbar to enable tracking for that specific email. Or turn it on globally so every email is tracked by default.
Works in replies and forwards
Read receipts work in new emails, replies, and forwards. Every compose window gets the tracking toggle. Track entire threads, not just initial sends.
No one knows you are tracking
The tracking pixel is invisible to the recipient. No "read receipt requested" popup. No notification to the other person. Completely silent.
Follow up at the right time
Stop guessing whether someone saw your email. When you see the blue double checks, you know they read it. Follow up when they are engaged, not when you are anxious.
Privacy-first design
CMDK does not read or store your email content. The tracking pixel only records open events (timestamp, count). Your emails stay private. Works locally in your browser.
Want the details behind the checkmarks? Read how Gmail read receipts actually work.
CMDK vs other Gmail email trackers
| Feature | CMDK | Mailtrack | Boomerang | Gmail on its own |
| Best for | Read receipts plus Gmail speed (command bar, snippets, split inbox) | Open tracking only | Scheduling plus read-receipt credits | Nothing extra to install |
| Read status on personal Gmail | Yes | Yes | Yes (credit-based) | No |
| Branding added to your emails | None | Free tier adds a “Sent with Mailtrack” line | No footer | None |
| Recipient asked to confirm | No | No | No | Yes, on Workspace when an admin turns receipts on |
| Cost | $79/year or $169 once, 15-day free trial | Free tier, paid plans | Credit-based add-on | Free |
| Full comparison | CMDK vs Mailtrack | CMDK vs Boomerang | Gmail read receipts guide |
cloudHQ and Streak are covered in the Gmail read receipts guide.
Common Questions
How do Gmail read receipts work in CMDK?
When you send an email with read receipts enabled, CMDK embeds an invisible 1x1 tracking pixel. When the recipient opens the email and their email client loads images, the pixel fires and CMDK records the open. You see the status change from a single gray check to double blue checks in your inbox.
Can the recipient see that I am tracking them?
No. The tracking pixel is invisible and does not trigger a popup for the recipient. Tracking stays silent.
Does CMDK read my emails to provide read receipts?
No. CMDK does not read or store your email content. The only data recorded is whether the email was opened, when, and how many times. Your email content stays private and is never sent to CMDK servers.
What are the different notification types?
CMDK offers four notification types based on when the email is opened: First Open (within 7 days of sending), Cold Revival (first open after 7+ days, useful for follow-up sequences), Re-engagement (re-opened after 24h+ gap), and Old Email Reopened (re-opened after 30+ days). You can enable or disable each type individually.
Can I track all emails automatically?
Yes. You can enable read receipts globally in Settings so every email you send is tracked by default. Or you can toggle tracking per email using the button in the compose toolbar.
Is CMDK an email tracker or read receipts?
Both. CMDK records when your sent email is opened and how many times, which is what an email tracker does, and shows it as read receipts: checkmarks next to each email in Gmail. It adds no branding to your emails.
Does CMDK have a free trial?
Yes. 15-day free trial with full access to all features including Read Receipts. No credit card required.
Have more questions? Contact Us ›
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