What bounce rate is safe for cold email?

Under 2%. That keeps you below every published sending-platform line we know of; Brevo's 2% is the lowest. HubSpot, Amazon SES and Instantly's default auto-pause act at 5%. Google and Yahoo publish no bounce percentage: their 0.3% figure is for spam complaints, and both tell senders to remove addresses that bounce.

My lead database already marks emails as verified. Why check again?

Because that status is from the database's last check, not today. People change jobs and mailboxes close between that check and your send. A fresh mailbox check right before import catches the ones that closed since.

Should I send to risky or catch-all addresses?

Not in the main campaign. A catch-all domain accepts every address at the SMTP stage, so no verifier can confirm the mailbox. Leave those rows out, or load them into their own smaller campaign at low daily volume so any bounces stay visible.

How much does it cost to verify a cold email list?

Sign in with Google and the first 100 email checks are free, once per account, with no card. After that, a one-time pack is $9 for 2,500 emails (credits never expire), or Pro is $29.99 a month with no cap on email verification.

Does verification make cold email compliant?

No. Verification tells you whether a mailbox exists; it says nothing about whether you may email it. Google's sender guidelines also say not to send to people who did not sign up, so cold outreach carries reputation risk whatever the list quality. Check the law where your recipients are.

Can I skip the CSV export?

If you use Instantly or Smartlead, subscribers can connect the sequencer and verify a campaign's leads directly. See the integration pages.

For cold email

Email verification for cold email

Guide · SimpleVerifier Team · Updated 20 Oct 2026

Verify every lead list after you export it and before it goes into your sequencer. A bounce counts against the sending inbox and domain, and the lowest published platform line is 2%. Export the CSV, run a mailbox check on every row, import only the valid file, and keep catch-all rows out of the main campaign.

Check 100 emails free See pricing

Google sign-in, no card. 7-day money-back guarantee on paid plans and packs.

The bounce math

Mailbox providers ask senders to stop mailing addresses that bounce. Google’s Email sender guidelines say to reduce volume when messages start bouncing and to unsubscribe recipients with multiple bounces. Yahoo’s Sender Best Practices say to remove invalid recipients promptly. Neither publishes a bounce percentage; their 0.3% line is for spam complaints.

The percentages come from the platforms you send through, and each is linked to its own help page. Instantly looks at a campaign once it has made 200 sends, so at a few hundred sends a day a bad list can pause on day one.

A worked example: at 300 new contacts a day, 2% allows 6 bounces a day. A list that bounces at 4% throws about 12 a day, twice that, from the first batch. Bounces arrive at about the same rate throughout a send, so a list over a line is over it from the start.

Run your own numbers in the bounce cost calculator

Published bounce lines

2%Brevohard bounces above this can suspend campaigns or the account
5%HubSpothard bounce rate in a month at which the account may be suspended
5%Instantlydefault auto-pause for a campaign, after 200+ sends
5%Amazon SESaccount placed under review (10% may pause sending)
10%Postmarkmust stay below this or sending is suspended

Read from each platform’s help page. Lines change; check your own platform.

The workflow: export, verify, import

Export from the lead source
Apollo, Clay, ZoomInfo, Hunter or your CRM, as a CSV. Keep the columns your copy uses.
Dedupe against past sends
Drop anyone already in a campaign or on your suppression list, so you only check rows you will send to.
Verify every address
Upload the CSV as it is. Every row gets a live mailbox check with catch-all detection, at up to 45 checks a minute.
Split by status
Download valid, risky and invalid files, each with your original columns kept.
Import the valid file into the sequencer
Map the email column, check the duplicate settings, and keep risky rows out of the main campaign.
Watch the first sends
Compare the live bounce rate with your sequencer's auto-pause line and stop early if it climbs.

What to do with each result

validSend
The mailbox server confirmed the address. This is the file that goes into the main campaign.
riskyHold, or send separately
Usually a catch-all domain, which accepts every address so no verifier can confirm the mailbox. Leave it out, or load it into its own smaller campaign at low daily volume so any bounces stay visible and away from the main one.
invalidDrop
The server said the mailbox does not exist, or the domain cannot take mail. Sending will bounce.

Step by step for your stack

Export clicks for the lead source, import clicks and column mapping for the sequencer, from each tool’s own help centre.

Export guides by tool

Skip the CSV

What it costs

100 checks free
Sign in with Google and your first 100 addresses get the full mailbox check, once per account. No card.
$9 for 2,500 emails
A one-time pack for a single campaign list. Credits never expire, so a list you clean twice a year still fits.
Pro: $29.99/mo
Unlimited email verification. Re-check every new export before it ships, at no extra cost per address.

Verify your lead list

Common questions

What bounce rate is safe for cold email?: Under 2%. That keeps you below every published sending-platform line we know of; Brevo's 2% is the lowest. HubSpot, Amazon SES and Instantly's default auto-pause act at 5%. Google and Yahoo publish no bounce percentage: their 0.3% figure is for spam complaints, and both tell senders to remove addresses that bounce.
My lead database already marks emails as verified. Why check again?: Because that status is from the database's last check, not today. People change jobs and mailboxes close between that check and your send. A fresh mailbox check right before import catches the ones that closed since.
Should I send to risky or catch-all addresses?: Not in the main campaign. A catch-all domain accepts every address at the SMTP stage, so no verifier can confirm the mailbox. Leave those rows out, or load them into their own smaller campaign at low daily volume so any bounces stay visible.
How much does it cost to verify a cold email list?: Sign in with Google and the first 100 email checks are free, once per account, with no card. After that, a one-time pack is $9 for 2,500 emails (credits never expire), or Pro is $29.99 a month with no cap on email verification.
Does verification make cold email compliant?: No. Verification tells you whether a mailbox exists; it says nothing about whether you may email it. Google's sender guidelines also say not to send to people who did not sign up, so cold outreach carries reputation risk whatever the list quality. Check the law where your recipients are.
Can I skip the CSV export?: If you use Instantly or Smartlead, subscribers can connect the sequencer and verify a campaign's leads directly. See the integration pages.