Your open rate isn't falling. Your list is.
Subscriber lists decay as people change jobs and abandon inboxes. Clean your list before big sends — export only the rows that are safe to send.
The list you built last year isn't the list you have.
People change jobs, domains die, inboxes fill and get abandoned — HubSpot pegs database decay at ~22.5% a year. The subscribers didn't unsubscribe; their addresses just quietly stopped existing.
So each send bounces a little more, inbox providers trust your domain a little less, and the open rate drifts down even though your writing didn't change. Cleaning before big sends keeps the bounces — and the damage — from compounding.
How you do it
Export subscribers
Download the list from your newsletter platform as a CSV.
Upload and run
The email column is found automatically; duplicates are skipped free. A five-figure list verifies while you write.
Export the clean list
Download deliverable-only rows and re-import. Keep risky rows in a separate segment and watch their engagement.
Repeat before big sends
Credits never expire, so buy once and clean on your own schedule — no subscription required.
Product UI shown with sample data.
Every answer is explained — and nobody gets emailed.
Four honest outcomes
deliverable, risky, undeliverable — or an honest unknown when a mailbox can't be confirmed, instead of a confident guess.
A reason for every row
A 0–100 score plus a machine-readable reason (no_mx, mailbox_not_found, disposable_domain…) you can act on and show your team.
No email is ever sent
The mailbox probe talks to the receiving server but always stops before any message — the people on your list never see anything.
What a 50,000-subscriber list costs
One credit checks one address. Pay once — credits never expire, and there's no subscription required. The full rate schedule is on the pricing page.
Frequently asked questions
Before any large send, and on a schedule if you send weekly — industry studies such as HubSpot's put database decay around 22.5% a year, so even a list that was clean last spring has drifted.
No. The mailbox check stops before any message is sent — nobody on your list receives anything, and nothing shows up in their inbox or spam folder.
Risky means the address exists but has a signal that hurts deliverability — a catch-all domain, a role inbox like info@, a disposable provider. Many senders move them to a separate segment and watch engagement rather than deleting them outright.
Keep reading: Email List Cleaning: When and How to Do It · What Is Email Verification? A Plain-English Guide