DNS-verified MX & SPF lookup — up to 5,000 emails per batch

Verify email addresses and identify the mail provider behind any domain

Paste or upload a list of email addresses. The Email Provider Filter checks MX and SPF DNS records to validate and sort them by their real mail provider — Google, Microsoft, Zoho, and 23+ others.

Verify Emails Free Learn how it works
Validating...0%
0
Total checked
0
Valid
0
Invalid
0
Inconclusive
0
Providers found
RESULTS READY

Provider distribution

Verified response data
EXPORT RESULTS

Download intelligence

Invalid emails0
Example output — sample data for demonstration
sokolov-results.csv — 8 emails checked
6
Valid
1
Invalid
1
Inconclusive
4
Providers
Google
3 emails
Microsoft
1 email
Zoho
1 email
ProtonMail
1 email
Sample data shown for illustration. Your real results will reflect live DNS lookups.

How it works

Three steps from raw list to sorted, provider-identified results.

1

Paste or upload

Add up to 5,000 email addresses by pasting them directly or uploading a .csv or .txt file. Duplicates are removed automatically.

2

DNS verification

The tool queries MX and SPF DNS records for each unique domain and matches them against known provider signatures for 26+ email providers.

3

Sort and export

Valid emails are grouped by provider. Copy or download sorted results as TXT or CSV. Invalid and inconclusive addresses are listed separately.

Built for email marketers and B2B sales teams

Everything you need to clean, sort, and understand your email lists.

✓
DNS-verified results
Real MX and SPF record lookups, not pattern matching. Learn about MX records.
∑
Bulk processing
Process up to 5,000 email addresses in a single batch, with automatic deduplication.
↓
Sorted exports
Copy or download results sorted by provider, as CSV or TXT, ready for your CRM or outreach tool.
🔍
26+ providers detected
Google, Microsoft, Yahoo, Zoho, ProtonMail, Amazon SES, Mailgun, SendGrid, and more.
⚠
Invalid & inconclusive
Addresses with syntax errors or no MX records are flagged, so you can clean your list before sending.
🔒
No account required
The tool is free and works without signing up. No data is stored — results stay in your browser.

Frequently asked questions

You can validate up to 5,000 email addresses in a single batch. The tool processes them in sequential groups of 500 and combines the results automatically.
The tool verifies email syntax, looks up MX and SPF DNS records for each domain, and matches the results against known provider signatures for 26+ email providers including Google, Microsoft, Yahoo, Zoho, and more.
No. The tool checks whether the domain can receive email and which provider handles it. It does not verify whether a specific mailbox exists at that provider.
Yes. The Email Provider Filter is free to use. No account or payment is required.

Email Provider Lookup & Domain Checker

The Email Provider Filter by Sokolov Systems identifies which mail provider handles email for any domain. By checking MX records and SPF signatures in DNS, the tool determines whether a domain uses Google Workspace, Microsoft 365, Zoho, ProtonMail, Yahoo, or another provider. This is useful for sales teams mapping email infrastructure, IT teams auditing domain configurations, and researchers studying email provider distribution.

Sokolov Systems develops software tools for legitimate business and email-domain intelligence purposes. Learn more about the company or read our guide on finding the email provider behind a domain.

Use the Tool Provider Lookup Domain Checker