Resources/Glossary/Cold email and lead gen
Bounce rate is the share of emails returned as undeliverable. In recruiting and sales outreach, a high bounce rate tells inbox providers you send to bad or outdated lists, which damages your sender reputation and pushes more of your future emails into spam.
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The share of emails returned as undeliverable. A high bounce rate tells inbox providers you send to bad lists.
Bounces come in two types. A hard bounce is a permanent failure, such as an address or domain that does not exist. A soft bounce is temporary, such as a full mailbox or a server that is down. Hard bounces matter most, because they show the list contains addresses nobody checked. Remove hard bounced addresses at once and watch addresses that soft bounce repeatedly.
Most bounce problems start with the list. Contact data goes stale as people change jobs, and guessed or scraped addresses often do not exist. Email verification before sending catches many bad addresses, though catch all domains cannot be fully confirmed. Sending from a new or unwarmed mailbox, or in large bursts, makes any bounce problem worse because providers have less history to judge you on.
Formula: Bounce rate = bounced emails ÷ emails sent × 100
Recruiters and agency business developers rely on email to reach candidates and clients. If bounces climb, inbox providers trust your domain less, and even emails to valid addresses start landing in spam. Keeping bounce rate low protects the domain your whole team sends from, keeps reply rates healthy and stops wasted effort on contacts who will never see your message.
Working from an old spreadsheet, a recruiter uploads 1,000 contacts and sends a campaign. Eighty emails bounce, an 8 percent bounce rate in this example, and replies drop on the next send. She pauses the campaign, runs the list through an email verification tool, removes invalid addresses and sends catch all contacts in small batches. Her next campaign bounces far less.
A few of the email verification tools in our directory, including our picks. Prices are the published starting price on the date we last checked.
Lower is always better, and many outreach teams aim to keep it as close to zero as they can with verified lists. Rather than chasing a single benchmark, watch for sudden rises, which usually mean a bad list or stale data, and fix the cause before sending more.
The usual causes are outdated contacts who changed jobs, guessed or scraped addresses, typos, purchased lists and domains that no longer exist. Sending large volumes from new mailboxes adds risk. Verifying lists, cleaning data regularly and removing hard bounces quickly fixes most of the problem.
No. Email bounce rate measures emails that could not be delivered. Website bounce rate is a web analytics measure of visitors who leave after viewing one page. They share a name but measure completely different things, so check which one a report means.
Written by recruiters at Work Insiders. Part of the recruiting and HR tech glossary. Updated October 2026.
