Verify Emails That Standard
Verification Can't Confirm
30-40% of B2B emails are on catch-all domains. Standard SMTP verification marks them "Risky" because it can't confirm if the mailbox exists. True-Send™ delivers definitive answers.
What is a Catch-All Domain?
A catch-all (or accept-all) email domain is configured to accept messages sent to any address at that domain, whether or not the specific mailbox exists.
For example, if company.com is catch-all, both john@company.com and xyz123@company.com will be accepted by the mail server—even if "xyz123" doesn't exist.
This creates a verification blind spot. Standard SMTP verification asks the server "does this mailbox exist?" and catch-all servers always answer "yes."
How mail servers respond
"Does fake@normal.com exist?" → No (550 User not found)
"Does fake@catchall.com exist?" → Yes (accepts all)
Why Catch-All Emails Are Risky
Sending to unverified catch-all addresses damages your deliverability and wastes resources.
High Bounce Rates
15-25% of catch-all emails bounce when sent. These hard bounces directly damage your sender reputation with ISPs like Gmail and Outlook.
Spam Folder Risk
High bounce rates trigger spam filters. Even your emails to valid addresses may land in spam folders, killing open rates and engagement.
Wasted Budget
Every email to a non-existent address costs money. For high-volume senders, unverified catch-all lists can waste thousands in ESP fees.
How Catch-All Verification Works
The only way to truly verify a catch-all email is to send a real email and see if it bounces.
Standard Verification First
We run full SMTP verification. Emails that pass are marked Valid. Emails that fail are marked Invalid. Catch-all domains are flagged as Risky.
Micro-Email Sent
For Risky emails, we send a tiny, invisible tracking email from a clean sender reputation. This email contains no marketing content.
Bounce Monitoring
We monitor for hard bounces over your selected window (24-72 hours). If the email bounces, the address doesn't exist.
Final Classification
Emails that don't bounce are confirmed Valid. Bounced emails are marked Invalid. You get definitive, actionable results.
Standard vs. Catch-All Verification
See what each verification method can and can't do.
| Feature | Standard SMTP | True-Send™ |
|---|---|---|
| Syntax & format check | ||
| Domain/MX validation | ||
| SMTP mailbox check | ||
| Confirms mailbox existsServer accepts all | ||
| Detects non-existent usersReturns 'Risky' | ||
| True-Send™ verification | ||
| Definitive deliverability |
When to Use Catch-All Verification
True-Send™ is most valuable when accuracy matters more than speed.
B2B Lead Lists
Corporate domains frequently use catch-all configurations. Verify leads before expensive outreach campaigns.
Enterprise Contacts
Large organizations often have catch-all enabled. Ensure your sales emails reach real decision-makers.
High-Value Campaigns
When sender reputation matters most, eliminate the guesswork from your most important email sends.
List Hygiene
Clean legacy lists that accumulated catch-all addresses over time. Reduce bounce rates permanently.
Frequently Asked Questions
What is a catch-all email domain?
A catch-all (or accept-all) domain is configured to accept emails sent to any address at that domain, even if the specific mailbox doesn't exist. For example, typo@company.com would be accepted even if there's no 'typo' user. This makes it impossible to verify individual addresses using standard SMTP checks.
Why can't standard verification confirm catch-all emails?
Standard SMTP verification works by asking the mail server if a specific address exists. Catch-all servers always respond 'yes' regardless of whether the actual mailbox exists. This creates a verification blind spot that only real email delivery can resolve.
Is True-Send™ safe for my sender reputation?
Yes. We send micro-emails from our own dedicated, high-reputation sending infrastructure—not from your domain. The emails are non-promotional, contain no links, and are designed specifically for verification. Your sender reputation is never at risk.
How long does catch-all verification take?
You choose the monitoring window: 24, 48, or 72 hours. Longer windows catch more delayed bounces but take more time. For most use cases, 48 hours provides the best balance of speed and accuracy.
What if an email doesn't bounce but the person never checks it?
True-Send™ verifies deliverability, not engagement. If an email is delivered without bouncing, the mailbox exists and can receive mail. Whether the recipient reads their email is a separate engagement concern, not a verification issue.
How accurate is catch-all verification?
True-Send™ achieves 99%+ accuracy on catch-all domains. The small margin accounts for edge cases like temporary server issues or delayed bounces outside the monitoring window. This is dramatically better than the 75-85% deliverability typical of unverified catch-all lists.
Stop Guessing. Start Knowing.
Catch-all verification is included in Growth and Scale plans. Get definitive deliverability for every email on your list.