Priority & keyword alerts, stale-email flags,meeting cost calculator, templates, attachment reminder & export tools for Outlook
Users
7
−1 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
2
0 in 30 days
Store rank
#218K
#183K among extensions
Version
1.8.0
updated 2 Sep 2026
Users
monthly, 2 months
Latest, 17 Oct 2026:7 usersMove the mouse over the chart for any month
Ratings count
monthly, 2 months
Latest, 17 Oct 2026:2 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 InboxSentry for Outlook
InboxSentry — Priority Senders, Stale-Email Alerts & Follow-Up Tracking for Outlook Web
Stop losing important emails in a crowded inbox. InboxSentry adds the tools Outlook on the web doesn't have — automatic priority-sender highlighting, stale-email alerts, follow-up tracking, contact insights, a meeting-cost calculator, one-click export, and a Schedule Send quick-picker — all inside outlook.office.com, outlook.office365.com, and outlook.live.com. No account, no server, no setup. Everything runs locally in your browser.
WHY INBOXSENTRY
Outlook is great at storing email. It's not great at telling you which email actually needs your attention. InboxSentry fixes that with a small floating panel and automatic on-page badges that surface what matters — a stale message from a client, an unanswered thread from your manager, a VIP contact you almost missed — without you having to scroll and re-read every subject line.
KEY FEATURES
⏰ Stale-Email Alerts (Automatic)
InboxSentry continuously scans your visible message list and stamps a badge directly onto any unread email that's sat unopened past a threshold you set (default: 3 days). No clicking required — it just works in the background. Open the email and its badge clears instantly. Priority senders (see below) get their own shorter threshold, so an important contact going quiet stands out sooner than a newsletter doing the same. Not ready to act on a flagged email right now? Snooze it for a day directly from the panel.
★ Priority Senders (Automatic)
Add a name, an email address, or an entire company domain (like @clientcompany.com) to your priority list, and every matching message gets a badge plus a side-accent in the inbox — automatically, no clicking required. Choose between two levels, Normal and High, so your most important contacts stand out even more. One click adds the sender of whatever email you're currently reading.
📌 Follow-Up Tracker
Track any email with a custom reminder window (in days). If you haven't marked it "replied" by the deadline, it moves to the top of your Tracked list and counts toward the badge on the floating InboxSentry button — a lightweight way to make sure requests, proposals, and questions you sent don't quietly die in someone else's inbox.
📊 Contact Insights
See who you actually hear from and who you actually email, with clean donut charts (top senders + "Other") and a full deduped list showing exact message counts. Scan your Inbox for "received from" insight and your Sent Items for "sent to" insight. Every sender is counted once — never once per email — and counts accumulate as you scroll and rescan, building a fuller picture over time.
💰 Meeting Cost Calculator
Ever wonder what that recurring status meeting is actually costing? Enter attendee count, an average salary band, currency, and duration, and InboxSentry estimates the cost per meeting — plus a projected annual cost if it's weekly, bi-weekly, or monthly. A live stopwatch mode ticks the running cost up in real time once the meeting starts, and your past calculations are saved to a simple history.
📤 One-Click Export
Export the open email as a clean, professional PDF or HTML file (letterhead-style layout — no clutter), or grab a quick Markdown or plain-text copy. Everything is generated locally in your browser; nothing is uploaded anywhere.
🗓️ Schedule Send Quick-Picker
One-click presets — Tomorrow 8am, Monday 9am, Friday EOD — plus a fully custom date-and-time picker, available both in the panel and as small pills injected right next to Outlook's own Send button. InboxSentry drives Outlook's own native "Send later" dialog as closely as it can automatically; you always confirm the final time yourself in Outlook's own confirmation screen. Times already in the past are always blocked.
☾ Light / Dark Theme
A single toggle in the panel header switches the whole tool between a light and a dark theme. It starts from your system preference and remembers whatever you choose after that.
WHO IT'S FOR
- Account managers and salespeople who can't afford to let a client email go stale
- Recruiters and hiring managers juggling dozens of candidate threads
- Consultants and freelancers who bill by relationship, not just by hour
- Managers who want a lightweight follow-up net without adopting a whole new CRM
- Anyone who has ever opened Outlook and thought "I know I'm forgetting to reply to something"
BUILT FOR OUTLOOK ON THE WEB
InboxSentry works everywhere you already use Outlook in the browser — no plugin to install inside Outlook itself, no admin approval workflow, no separate app to check. Install it, and a small round button appears in the bottom-right corner of your inbox.
YOUR DATA STAYS ON YOUR DEVICE
InboxSentry makes no network requests of its own. Every setting, every tracked follow-up, every priority sender, every contact-insight snapshot, and every meeting-cost calculation is stored using Chrome's local storage, on your device only. Nothing is sent to us, to Microsoft, or to any third party. There's no account to create and no server in the middle. See the full privacy policy for details.
FREQUENTLY ASKED
Does this work with Outlook.com (personal accounts) or just work/school accounts?
Both — InboxSentry runs on outlook.office.com and outlook.office365.com (work/school) as well as outlook.live.com (personal Outlook.com).
Does it read my email content and send it anywhere?
No. InboxSentry reads what's already rendered on the page — subject, sender, unread status — to power its features, and everything stays local to your browser. It has no server component and makes no external network calls.
Will Schedule Send actually send my email for me?
No — and it's designed not to. InboxSentry gets you as close as possible to Outlook's own scheduling dialog and copies the target time to your clipboard as a fallback, but it never clicks Outlook's final Send/Schedule confirmation on your behalf. You always confirm in Outlook's own UI.
Does the Conta…