What is list cleaning?
Cleaning a lead list means getting its email column into a state a sending tool can use: one address per row, written the same way every time, each address once. It removes rows that cannot be sent, such as a missing or malformed address, and points out role mailboxes like info@, which reach a team rather than a person.
Reading the result
Pick the email column (found for you, and changeable) and the counts follow your options: rows kept, duplicates, invalid addresses, rows with no email and role addresses. The cleaned file keeps your columns and delimiter, with each email trimmed and lowercased. The removed rows come as a second file with the reason in its first column. The file is read on this page and never uploaded.
Common problems it finds
The same person twice
A check that compares the exact text treats Jane@Acme.com and " jane@acme.com" as two people. This one compares addresses trimmed and without case, and keeps the first row for each.
Addresses that are not addresses
A name in the email column, two addresses in one cell, a missing @ or a domain with no dot. The check is the one this site's own forms use, and it reads syntax only: whether a mailbox exists takes a verification service.
Role addresses
RFC 2142 names 15 mailboxes for functions rather than people, such as info@, sales@, support@ and postmaster@. They usually reach a shared inbox, so an email written to one person is read by whoever watches it. They are counted, and removed only if you tick the box.
A file that reads wrong
Excel in much of Europe saves CSV with semicolons, and older exports are not UTF-8. The cleaner detects comma, semicolon or tab, falls back to Windows-1252 when the bytes are not UTF-8, and says when a stray quote ran one field into the lines after it.