This extension adds a visual alert in Gmail whenever external recipients or senders are detected in the From, To, Cc, or Bcc fields.
Users
4
−1 in 30 days
Rating
0.0 / 5
unchanged in 30 days
Ratings
0
0 in 30 days
Store rank
#286K
#236K among extensions
Version
2.0
updated 13 Dec 2025
Users
monthly, 11 months
Latest, 15 Oct 2026:4 usersMove the mouse over the chart for any month
Ratings count
monthly, 11 months
Latest, 15 Oct 2026:0 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About Smart Gmail External Sender Alert
"Prevent Accidental Data Leaks and Phishing Risks in Gmail with Smart External Alerts
Have you ever accidentally sent a confidential email or internal information outside your company — or received a suspicious message from an unknown external sender? A single oversight can lead to data exposure, compliance issues, or even phishing attacks.
External Email Alert acts as your intelligent, built-in safety shield within Gmail—helping you identify external communication risks before you act.
Our extension automatically checks email domains while you compose outgoing emails and while you read incoming emails. If an address from outside your organization’s domain is detected in the From, To, Cc, or Bcc fields, it displays a clear, unmissable alert so you can stay alert and make informed decisions.
Key Features
⚠️ Automatic External Detection
Instantly flags any recipient or sender that does not belong to your internal domain—both incoming and outgoing emails.
✉️ Protect Against Mis-send & Phishing Risks
Alerts when you might unintentionally share sensitive data—or when receiving external emails that may be risky.
🎨 Seamless Gmail Integration
Alert banners blend perfectly into the Gmail interface without interrupting your workflow.
⚙️ User Preferences
Custom settings stored locally for a tailored, consistent experience every time.
🔒 Secure & Private
We never store, transmit, or read your email content. Only domain-level checks ensure privacy and safety."