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Mail7

Bulk check

Bulk email checker

Paste a list 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

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

Bulk email validation is essential for businesses and organizations that manage large email lists. It helps identify invalid, inactive, or non-existent email addresses before sending campaigns, improving deliverability rates and protecting 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

  1. Clean your data first: Remove duplicates and format emails properly

  2. Validate regularly: Check your lists every 3-6 months for best results

  3. Monitor results: Track validation rates to identify data quality issues

  4. 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