Email decay protection
Every email list quietly goes bad over time. mailfloss re-verifies your existing subscribers on a schedule — catching bounces, clearing dead addresses, and fixing typos — so your list stays deliverable without manual cleanups.
What is email decay?
Email decay is the natural process by which a healthy email list goes bad over time — subscribers change jobs, abandon old inboxes, or switch providers, so addresses that were valid at signup quietly stop working. Email lists decay by about 22.5% per year (MarketingSherpa). Decay protection re-verifies your existing subscribers on a schedule and removes or fixes the dead ones before they hurt deliverability. mailfloss runs this automatically inside your connected email platform.
Why do email lists decay?
Every email list decays whether or not you send to it. People change jobs and lose their work addresses, abandon old personal inboxes, or switch email providers; some abandoned addresses are later recycled by providers into spam traps. None of this announces itself — it only surfaces when a message bounces or a spam complaint lands, and by then the hit to your sender reputation has already happened.
The longer an address sits without being re-checked, the more likely it has quietly gone bad. That is why list quality is not something you fix once: decay is driven by your subscribers’ lives, so it keeps accumulating in the background between every campaign.
How much of an email list decays?
Email decay is faster than most senders expect: MarketingSherpa’s research puts contact-data decay at 2.1% per month — about 22.5% per year, or more than one in five addresses going bad within twelve months. A list you cleaned once and left alone starts drifting immediately, because decay tracks your subscribers’ lives rather than your sending schedule.
That is why a single one-off verification goes stale, and why decay protection has to run on a recurring schedule instead of as a one-time cleanup. Catching decayed addresses continuously keeps your bounce rate low and your sender reputation intact.
How often should you re-validate an email list?
Re-validate your email list at least every 90 days — and every 30 days is better, especially if the list grows quickly or you email every week. Fast-growing and high-volume lists accumulate decayed addresses faster, so they need the tighter monthly cadence; a small, slow-growing list can stretch toward the 90-day end.
The goal is to catch decayed addresses before your next campaign, not after a bounce spike — so the safest cadence is really “continuously, in the background,” rather than a date you have to remember on a calendar.
How does mailfloss protect against email decay?
mailfloss protects against decay by re-verifying the subscribers you already have on a schedule you set, directly inside your connected email platform — no CSV exports or re-imports. It catches hard bounces, clears risky and disposable addresses, and fixes common typos like gmial.com instead of deleting the subscriber, so real people stay on your list.
New signups are checked in real time and older contacts are re-scanned continuously, so your list stays deliverable without manual cleanups. Connect once, choose your cleanup rules, and decay protection runs quietly from then on.
