Bulk check
Bulk email checker
Bulk email verification for a whole list: paste addresses or drop a CSV. Every address goes through the same four stages as a single check, and comes back as Valid, Not Valid or Unknown, with the reason attached.
- Per file, free plan
- 1,000
- Per file, Business
- 100,000
- Formats
- .txt and .csv
- Unknown results
- Never billed
Your list
0 emails entered
Upload an email list
Click to upload, or drag a file here
.txt or .csv · one address per line, or a column of them
Nothing is sent to the addresses. Results are yours to download as CSV.
What comes back
A verdict per row, and the reason behind it
The CSV carries every column you see on screen, so the list you hand to your email tool already knows which addresses to skip.
Paste or upload
One address per line in the box, or a .txt file, or a multi-column .csv where you pick the column that holds the addresses.
Live progress
A counter, a rate and a cancel button. Stop halfway and you can still download everything checked so far.
Three counters, not two
Valid, Not Valid and Unknown are counted separately. Unknown rows are not quietly folded into either side.
Your list stays yours
The uploaded file is discarded as soon as the job finishes. Results auto-delete after 7 to 90 days depending on your plan, and you can delete a job yourself at any time. We never sell or share uploaded lists. How we handle your list
Guide
Bulk email validation guide
A bulk email verifier checks a whole list in one run instead of one address at a time. Bulk email validation finds invalid, inactive and non-existent addresses before a campaign goes out, which keeps bounces down and protects your sender reputation.
Why use bulk email validation?
Improve deliverability: Remove invalid addresses that could harm your sender reputation
Save costs: Avoid sending emails to non-existent addresses
Better engagement: Focus on valid addresses for higher open rates
Compliance: Maintain clean lists for GDPR and other regulations
Processing limits and recommendations
- Per-file limit
- Depends on your plan: 1,000 on the free tier, up to 100,000 on Business
- Processing time
- Approximately 1-2 seconds per email address
- Export
- Download a CSV file with detailed validation results
- File formats
- Text files (.txt) with one email address per line, or multi-column CSV files with column selection
Best practices for bulk validation
Clean your data first: Remove duplicates and format emails properly
Validate regularly: Check your lists every 3-6 months for best results
Monitor results: Track validation rates to identify data quality issues
Use for campaigns: Focus on valid addresses for better engagement rates
Understanding validation results
- Valid
- Passed all validation checks and can receive emails
- Not Valid
- Failed a validation check: bad format, no mail server, or the mailbox doesn't exist
- Unknown
- The mail server would not confirm the mailbox, usually a catch-all domain, greylisting or anti-spam protection. Keep these addresses and let engagement decide
Questions
Bulk email checker FAQ
Is this bulk email verifier free?
Yes. Without an account you can try a sample of 10 addresses. A free account checks up to 1,000 addresses per file and 1,000 verified addresses a month, no card needed. Unknown results are never counted against the quota.
How many emails can I verify at once?
Up to 1,000 per file on the free plan, 5,000 on Starter, 25,000 on Pro and 100,000 on Business. Larger lists can be split into several files.
What file formats does the bulk email checker accept?
Plain text (.txt) with one address per line, or a CSV with any number of columns. For a CSV you pick the column that holds the addresses, and the export keeps the verdict and reason for every row.
What is the difference between bulk email validation and bulk email verification?
In practice the terms mean the same job. Validation usually refers to the format and domain checks, verification to asking the mail server whether the mailbox exists. Mail7 runs both for every address: syntax, MX records, then an SMTP check.
Why are some addresses marked Unknown?
Some mail servers accept every address (catch-all), delay unknown senders (greylisting) or hide their recipients on purpose. When the server will not confirm the mailbox we say Unknown instead of guessing, and we do not bill for it.
Does the bulk email validator flag disposable and duplicate addresses?
Yes. Disposable domains and repeated addresses get a note next to the result, so you can drop them from the list before sending.