Clean your email list — validate, dedupe, and spot role accounts
Paste an email list and get a clean, deduplicated list back, plus a row-by-row report of every invalid, duplicate, or role address removed.
🔒 100% client-side · zero server upload
Domains
What was removed
Malaysian rules & edge cases
Syntax first, mailbox second. This cleaner checks RFC-style syntax (one @, a dotted domain, a TLD of at least two letters) and lowercases everything, because ALI@Gmail.com and ali@gmail.com are the same mailbox. It cannot check whether a mailbox actually exists without sending mail — that check would need a server, which this tool never uses.
| Rule | What happens | Typical Malaysian case |
|---|---|---|
| Invalid syntax | xxx, xxx@, @gmail.com are dropped and reported | CRM exports with truncated fields and half-typed addresses |
| Duplicates | Case-insensitive dedupe: Ahmad@KEDAI.com = ahmad@kedai.com | Programme lists merged from Shopee buyers and walk-in sign-ups |
| Role accounts | admin, info, hello, sales, support, noreply and similar are flagged; optionally removed | Broadcast lists full of company inboxes nobody reads |
| Domain stats | Counts per domain: gmail.com, yahoo.com, outlook.com, .my domains | Seeing that 80% of a Malaysian customer list is free mail |
| CSV mode | Outputs email,domain,is_role for spreadsheet review | Handover to a mail tool like SifuMail business email hosting |
Empty lines are dropped and reported, CRLF line endings from Excel and Notepad are handled automatically, and a trailing newline at the end of the file does not create a phantom blank row. Everything runs in your browser: no upload, no server, no account.
Before and after
Before
Ali@GMAIL.com
admin@kedai.com.my
xxx@
ali@gmail.com
Sara@Yahoo.comAfter
ali@gmail.com
admin@kedai.com.my
sara@yahoo.comHow it works
- Paste your email list into the INPUT box, or press "Load sample data" to see a Malaysian example.
- Choose whether to remove role accounts and whether to output plain lines or CSV with domain stats.
- Press Run. The OUTPUT box holds the clean list, and the report below lists every invalid, duplicate, or role address that was removed and why.
FAQ
Does this upload my email list to a server?
No. The whole tool is static JavaScript that runs in your browser. You can confirm zero requests in your browser Network tab when you press Run, which matters for customer email lists.
Can it prove a mailbox actually exists?
No. It validates syntax, deduplicates, and flags role accounts. Proving a mailbox exists requires a mail server check, which would need to upload your data. For business sending, use a proper hosting provider.
Which duplicates are kept?
The first occurrence. Every later case-variant of the same address is removed and reported by line number, so you can trace exactly what disappeared.
What counts as a role account?
Local parts like admin, info, hello, sales, support, noreply, contact, billing and similar shared inboxes. They are flagged by default and only removed when you tick the option.