Email activity data: know whichaddresses are already dead.

22.5% of the average list decays every year. Verifox engagement data tracks last-open dates, click recency, reply signals, and device patterns, then rolls them into one recency score per address. You see exactly who still reads you and who left.

Activity Timeline

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j.nguyen@acme.co

2d ago

marketing@bigco.io

18d ago

sara.j@startup.com

47d ago

info@oldcorp.net

93d ago

hello@shutdownco.com

185d ago

test@gone.org

365d ago

Updated every 24 hours · Works with any ESP · API included


The behavioral layer

What is email activity data?

Email activity data is behavioral evidence that a real person still uses a mailbox: when it last opened a message, how recently it clicked, whether it replies, and what devices it reads on. A standard verification check tells you a mailbox exists. Activity data tells you whether anyone is home. Verifox tracks six engagement signals per address and compresses them into a single 0 to 100 recency score, recomputed every 24 hours, so a list of 50,000 unknowns becomes four clean segments: active, fading, dormant, and dead.

The reason it matters is decay. Around 22.5% of a typical list goes stale every year. People change jobs, abandon personal accounts, and companies fold or migrate domains. Few of those addresses bounce right away. They sit on your list, drag open rates down, and quietly teach Gmail and Outlook that your mail gets ignored. Mailbox providers weigh engagement heavily when choosing between the inbox and the spam folder, so every dead address you keep mailing lowers placement for the readers who want you. Our email verification engine catches addresses that no longer exist. Activity data catches the ones that exist but stopped listening.

In practice you use it three ways. Segment: write differently to engaged readers than to fading ones. Sunset: follow the five-stage policy below for when to nudge, throttle, suppress, and remove. Protect: pair it with AI email scoring before a big send and an inbox placement test after, so you can measure the payoff. And if your domain is starting cold, email warmup plus an activity-cleaned list is the fastest route back to the inbox.


Where your budget goes

You are paying to send to ghosts.List decay is the silent line item.

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Average annual list decay rate

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Activity data refresh cycle

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Reputation recovery time

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Higher bounce rate without cleanup

Verifox fox mascot frowning at email list decay

A 50K list at 22.5% annual decay carries 11,250 dead addresses you are still paying your ESP to send to.


What we actually measure

Six engagement signals, onerecency score per address.

We don't just check if an email exists. We read behavioral signals to determine whether a real person is actively using that mailbox, then score it 0 to 100.

Last Open

Timestamp of the most recent email open. The strongest engagement signal. An address that opened something last week is alive. One silent for 6 months is almost certainly abandoned.


Click Activity

Click-through events show active interest beyond passive opens. No clicks in 90+ days means your content is being ignored, even when opens register from preview-pane triggers.


Reply Signals

Replies prove a real human operates the mailbox. We track outbound patterns from the address. This separates real users from role accounts and aliases nobody reads.


Device Diversity

Active mailboxes show varied access: mobile, desktop, webmail. A single device type or no fingerprint at all suggests the address is dormant or automated.


Domain Health

Aggregate engagement data at the domain level. If open rates decline across all addresses at a domain, the company may have changed providers, moved domains, or shut down.


Recency Score

A composite 0-100 score combining all five signals into a single freshness metric. Updated every 24 hours. Above 70 = active. Below 30 = stale. Below 10 = dead.


Engagement half-life

After 90 days without an open, youremail has a coin-flip chance of landing.

100%75%50%25%0d30d60d90d180d95%78%54%22%8%

After 30 days of inactivity, deliverability drops sharply. By 90 days, more than half your emails to that address are landing in spam or bouncing. By 180 days, the address is dead weight.


Privacy-first · We track engagement signals, not personal data or message content · GDPR compliant · SOC 2 Type II


The rulebook

A sunset policy tells you exactly whento nudge, throttle, or cut loose.

A sunset policy defines what to do at each inactivity milestone. Without one, dormant addresses accumulate silently and erode deliverability for everyone else.

30 days

Move to re-engagement segment

Send a targeted 'We miss you' sequence while the address still has a pulse. The earlier the nudge, the better the return rate.

60 days

Reduce send frequency

Drop from weekly to monthly. Protect your sender reputation while giving them space.

90 days

Send final re-engagement

One last email: 'Do you still want to hear from us?' with a clear one-click resubscribe.

120 days

Suppress from campaigns

Stop sending marketing emails. Keep them in your database but remove from all active segments.

180+ days

Remove from list

Delete or archive. At this point, the address is likely abandoned, a spam trap, or filtering you to trash.


Three steps

Drop your list. We tell youwho is alive and who is not.

01

Drop your list

CSV, Excel, or TXT. Drag and drop, paste, or connect via API. Any size, from 100 addresses to 10 million.

02

We scan engagement signals

Each address is checked for opens, clicks, replies, device patterns, and domain health, then scored for recency.

03

Download segmented results

Active, fading, dormant, and dead. Each address comes back categorized with a clear recommended action.


Common questions

Activity data, answered straight

What teams ask before they run engagement data on a list: how last-open tracking works, what a recency score means, what it costs, and where the legal lines sit.

What engagement signals does Verifox track?

Six signals per address: last-open timestamp, click recency, reply patterns, device diversity, domain-level engagement trends, and a composite 0 to 100 recency score that rolls the first five into a single freshness number. No mailbox content is ever read. The signals describe whether a mailbox is in active use, not what is inside it, which is exactly the question a list owner needs answered before the next send.

How do you know when an address last opened an email?

We aggregate engagement events across the sending ecosystem: open pings, click-throughs, reply activity, and the device fingerprints tied to an address over time. The most recent confirmed event becomes the last-open date, and the gap between open, click, and reply events feeds the recency score. Preview-pane auto-opens are discounted, so a mailbox that technically registers opens but never clicks or replies still drifts toward the dormant segment.

What is a recency score?

A recency score is a 0 to 100 freshness rating for one address. Above 70, the mailbox engaged recently and is safe to email. Between 30 and 70 it is fading and belongs in a re-engagement segment. Below 30 it is stale, and below 10 it is effectively dead. Scores recompute every 24 hours, so a subscriber who comes back climbs out of the dormant bucket on their own.

What is a sunset policy and why do I need one?

A sunset policy is a written rulebook for inactivity milestones: re-engage at 30 days, throttle at 60, send a final "still want these?" at 90, suppress at 120, remove at 180. Without one, dead addresses accumulate silently, bounce and complaint rates creep up, and Gmail and Outlook start filtering you for everyone, including the readers who still open every send. The full five-stage policy is laid out above on this page.

Is tracking email engagement data GDPR compliant?

Yes, used correctly. Activity data measures engagement events, not message content or personal attributes, and Verifox processes addresses in memory without storing, logging, or selling them. We are SOC 2 Type II audited. You remain the controller of your own list, and suppressing subscribers who stopped responding is widely treated as good practice under GDPR. Details live in our privacy policy.

How fresh is the activity data?

Recency scores refresh on a 24-hour cycle, so the same list uploaded a month apart shows addresses migrating between segments as people return or go quiet. Lookups are fast too: roughly 380 ms median for a single address, sub-50 ms when cached, and bulk jobs run at about 10,000 emails per minute on the standard tier. A 50,000-row list finishes in minutes.

How is activity data different from email verification?

Verification answers "does this mailbox exist and accept mail?" through our 9-point engine: syntax, MX records, SMTP handshake, catch-all detection, and more. Activity data answers the next question: does anyone still read it? A mailbox can verify perfectly and sit abandoned for two years. Run email verification first to strip invalid addresses, then use engagement data to decide who actually deserves your sends.

Can I pull activity data through the API?

Yes. The REST API returns the recency score, last-activity window, and segment label alongside the standard verification verdict, so one call covers both checks. Request and response shapes are documented in the API reference. If you build with AI agents, the same fields are exposed through our native MCP server, so Claude, Cursor, or a custom agent can query your list without glue code.

How much does email activity data cost?

It runs on the same pay-as-you-go credits as verification. Sign up free and you get 1,000 credits, or 2,500 when you register with a work address. No card required, and credits never expire. Volume rates are shown for your region on the pricing page, with discounts that deepen as usage grows.

Which addresses should I actually remove from my list?

Start with anything silent for 180 days or more after a re-engagement attempt. Those addresses are abandoned, recycled, or filtering you to trash, and some turn into spam traps. Before deleting, run them through the email bounce checker to confirm hard-bounce risk, and watch your domain with deliverability monitoring after the cut. Most teams see placement improve within two or three sends.

Fox mascot dozing beside a dormant email list

Find out who went dark on your list.

Sign up, get 1,000 free credits (2,500 with a work email), and upload your list. Every address comes back verified and segmented by engagement, usually within minutes. No card, and credits never expire.

Updated every 24 hours · API access · Works with any ESP