Upload Excel / CSV File
Drop your contacts spreadsheet here
Drop your file here
or click to browse your computer
XLSX
XLS
CSV
ODS
Max 20 MB
Validation Levels
🔤
Level 1 · Syntax
RFC 5321 email format check
🌐
Level 2 · Domain
DNS A / AAAA record lookup
📬
Level 3 · MX Record
Mail server presence check
🤝
Level 4 · SMTP
Live handshake verification
What to expect
- Duplicate emails validated only once
- Results cached — re-upload same list instantly
- Pause and resume at any time
- Original columns preserved
- Download updated Excel with results
- SMTP check depends on server port 25 access