SendGuard

Gmail accidental-send prevention — no account connection

SendGuard is a Gmail-only Chrome extension that helps prevent accidental sends and mistakes to people outside your company. Built for people who email customers, partners, and large groups — it quietly pauses only at the hard-to-undo moment, right before Send.

No Gmail API or OAuth. No SendGuard server. Email content and recipient addresses are not stored — only your settings. Checks run entirely in the browser.

Features

What SendGuard does

🔒 No account hook-up

  • No Gmail API / OAuth — no Gmail account connection
  • No SendGuard backend — checks only inside your browser
  • Does not store email body or recipient addresses — settings only

✍️ While you compose

  • External recipient hint — yellow compose notice when To/Cc/Bcc includes addresses outside your configured company domain(s)
  • Domain labels — “company” / “external” badges next to recipient chips

⏸️ Pause before common mistakes

  • Missing attachment — words like “attached” but no file or Google Drive link (quotes and signatures excluded)
  • Unfilled placeholders — [name], {{name}}, OOO, TBD, etc.
  • Empty subject — trying to send with no subject
  • Empty body — only quoted text or signature in a reply/forward
  • Too many recipients — To+Cc+Bcc over your threshold (mis-sent reply-all / bulk send); threshold adjustable
  • Sensitive words + external — confidential-style terms when external recipients are present (editable word list)

📤 Send interception

Intercepts Send, Ctrl/Cmd+Enter, and scheduled send. You can always choose “Send anyway”. Attachment warnings can appear in a SendGuard Shadow DOM modal (alongside Gmail’s native confirm when applicable).

🌐 Language & settings

  • Default attachment, placeholder, and sensitive-word lists follow UI language (Korean / English / Japanese)
  • Settings → Word management — edit chips; toggle rules from notifications
  • Popup & settings theme: system / light / dark
  • Settings → Chrome sync; Gmail UI state checks → local only
Guide

🚀 How to use

  • Install SendGuard and open Gmail in Chrome
  • Set your company domain(s) and adjust rules in Options
  • Compose as usual — external hints and domain labels appear while writing
  • When a rule triggers at Send, review the pause — then fix or Send anyway
Users

Perfect for

  • People who frequently email customers, partners, or large groups
  • Teams who want external-recipient and reply-all guardrails without Gmail API access
  • Anyone who has sent “attached” without an attachment or hit Reply-all by mistake
Privacy

🔒 Privacy

  • No backend / no remote mail analysis
  • No Gmail API / OAuth / send history collection
  • Settings → chrome.storage.sync; Gmail UI state checks → chrome.storage.local only
  • Email content and recipient addresses are not stored by SendGuard

SendGuard — pause before the send you cannot take back.

URL

Chrome Web Store URLs

Register these paths in the Chrome Web Store listing for SendGuard.

Store listing

Visitors are redirected by country (KR/JP) or browser language to /sendguard/en, /ko, or /ja.