InboxKit provides a fast and highly accurate bulk email validation tool to help you clean your outreach lists before sending. This ensures better deliverability, fewer bounces, and a stronger sender reputation across your campaigns.
In this guide, you’ll learn:
What Email Validation does
How credits work
How to upload and validate your email list
How to review and download your results
Understanding validation statuses
Email Validation helps you verify large email lists before sending. With InboxKit, you can:
Validate thousands of emails in one upload
Identify valid, invalid, catch-all, and unknown emails
Improve deliverability and protect your domain reputation
Avoid sending to risky or bouncing addresses
1 credit = 1,000 validations
E.g., if you upload 5,000 emails → cost = 5 credits
The platform automatically calculates the exact credit cost before you start validation.
You can view your available credits at the top of the Email Validation page.
In the left sidebar, click Addons
Select Email Validation
You’ll see:
Available Credits
Total emails you can validate
Credit rate (1 credit = 1,000 validations)
Click Choose File
Upload a CSV file
Max size: 10 MB
Max records per file: 10,000
Your CSV should contain at least one column with email addresses.
Once the file loads:
InboxKit will display a preview of your sheet
On the right side, map the column that contains the email addresses
(Usually auto-detected as “email”)
At the bottom-right, you’ll see:
Total emails
Credit cost (e.g., 0.005 credits for 5 emails)
If needed, you can:
Turn ON “Use first row as header”
Edit cells directly
Re-upload the file
Save the edited file
When ready → click Start Validation
After clicking Start Validation:
Status becomes Processing
System starts validating your emails
Large lists may take a few minutes
You can leave the page — validation continues in the background.
Scroll down to the Validation History section.
Here you can see:
Status → Processing / Completed / Failed
Total emails
Unique emails
Valid Emails
Catch-All
Invalid Emails
Unknown Emails
Download options
Once validation is finished, the status will update to Completed.
Click Download → choose format:
CSV
TSV
XLSX
Each result file includes segregated categories so you can upload clean lists into Sequencer or any outreach tool.
Status
Meaning
Valid | Safe to send emails. |
Invalid | Invalid mailbox — will bounce. Avoid using. |
Catch-all | Domain accepts all emails; may still bounce. Use with caution. |
Unknown | Could not verify; usually temporary server blocks. Optional to use. |
Always validate large lists before sending
Remove invalid emails completely
Send to catch-all only if needed
Revalidate older lists every 30–60 days
Keep bounce rates below 3% for best inbox placement
Path: Addons → Email Validation
Steps:
Upload CSV
Map email column
Start Validation
Check Validation History
Download Results
Cost:
1 credit = 1,000 validations
