Find addresses that will bounce before you send. Protect your sender reputation and keep bounce rates below 2%.
Multi-layer SMTP verification identifies hard and soft bounce risks before your emails are sent. Protect your sender score and reach more inboxes.
A high bounce rate triggers ISP penalties that compound over time.
ISPs track bounce rates and penalize senders who exceed safe thresholds, reducing future inbox placement.
Once your reputation drops, more emails are filtered to spam — even to valid addresses.
Persistent high bounce rates can get your domain or IP added to email blacklists.
Every bounced email costs a credit and contributes nothing. Clean lists before you pay per send.
Four verification steps run on every address to assess bounce risk.
Validates address format and detects typos before any network requests are made.
Confirms the domain exists and resolves MX records to verify mail delivery is configured.
Connects to the mail server to test whether the specific mailbox accepts incoming mail.
Combines all signals into a 0–100 risk score with a hard/soft/unknown bounce classification.
85%
Bounce Reduction
Average list improvement
<2%
Target Bounce Rate
After list cleaning
50K/hr
Processing Speed
Bulk verification rate
99.9%
Accuracy
SMTP-level verification
Each tool addresses a specific email deliverability risk.
Check individual emails for validity, deliverability, and reputation. No account required.
Identify and block temporary email services before they pollute your list.
Identify accept-all mail servers that mask actual mailbox existence.
Filter out generic role addresses like info@, support@, and admin@ that hurt engagement.
It identifies addresses that will bounce before you send. Hard bounces are permanent failures (mailbox doesn't exist). Soft bounces are temporary issues (full inbox). We detect both types so you can remove risky addresses from your list.
We check each email in multiple steps: syntax validation, domain and MX record checks, and a direct SMTP connection to test mailbox deliverability. The entire process runs at 99.9% accuracy in under 3 seconds per address.
Most users see an 85% reduction in bounces after cleaning. If your list bounces at 15%, expect to get below 2% after verification. Results are visible immediately.
Yes. Upload a CSV file and we'll process thousands of addresses for bounce risk. The API also supports real-time single checks for forms and sign-ups.
Cached results return in under 200ms, and full SMTP verification completes in 1–3 seconds on average. Bulk processing handles 50,000 addresses per hour.
Yes. Every account gets 100 free checks per day with no credit card required. You can test all features including API access before upgrading.
A hard bounce is a permanent delivery failure — the email address doesn't exist, the domain is invalid, or the mail server rejected the message permanently. You should remove hard bounces from your list immediately. A soft bounce is a temporary failure — the mailbox is full, the server was unavailable, or the message was too large. Soft bounces may succeed on retry, but addresses that soft bounce repeatedly should also be removed. BillionVerify's email bounce checker detects both hard and soft bounce risks before you send.
To reduce bounce rate: (1) verify your list with an email bounce checker before every send to remove invalid addresses, (2) remove hard bounces immediately and monitor soft bounces, (3) use double opt-in for new subscribers, (4) avoid purchasing email lists, and (5) clean inactive subscribers every 6 months. Most senders see bounce rates drop by 85% after using BillionVerify's bounce detection before a campaign.
Email bounce detection works by running SMTP verification on each address before you send — testing syntax, domain existence, MX records, and whether the specific mailbox accepts incoming mail. This identifies hard bounce risks (non-existent mailboxes) and risky addresses (catch-all domains, role accounts, disposable emails) without sending a real email. The entire check completes in under 3 seconds per address.
Check your email list for hard bounces before you send. Reduce bounce rates below 2% and protect your sender reputation.
100 free checks daily · 85% average bounce reduction · No credit card required
