The Scenario
You've just finished a lead gen campaign. Column A of your Excel workbook has 2,000 email addresses, collected from a form over the past three weeks, and your ESP import window opens tomorrow morning. The campaign manager wants the list clean before it goes in — no syntax garbage, no disposable addresses, no contacts with dead MX records. You've been handed this task at 4 PM.
The bad version:
- Export column A to CSV, open the Mailboxlayer API docs, figure out how to run a batch lookup or string together 2,000 individual API calls from the terminal
- Get back a JSON file with 2,000 objects, each containing six or seven fields, and manually match each result row back to the right row in the workbook
- Paste in syntax_valid, smtp_check, mx_found, disposable one column at a time, then eyeball which rows get a 'Keep' and which get a 'Remove'
The import window is tomorrow. You're not supposed to be a data engineer — you're supposed to be the person who decides who gets the email.
The Easy Way: One Prompt in SheetXAI
SheetXAI is an AI agent that lives inside your Excel workbook. It reads your data, understands the column structure, and uses its built-in Mailboxlayer integration to validate every email and write the results back. You don't configure a template or parse a JSON file. You ask.
Validate every email in column A using Mailboxlayer and write to columns B–E: syntax_valid, smtp_check, mx_found, and disposable — mark column F as 'Keep' or 'Remove' based on the results
What You Get
- Column B: syntax_valid — TRUE or FALSE per row, catching malformed addresses immediately
- Column C: smtp_check — whether the mail server confirmed the address exists
- Column D: mx_found — whether a mail exchange record exists for that domain
- Column E: disposable — flags temporary-inbox providers like Mailinator or Guerrilla Mail
- Column F: 'Keep' for addresses that pass all checks, 'Remove' for anything that failed syntax, has no MX, or came from a disposable domain
What If the Data Is Not Quite Ready
Some emails have leading or trailing whitespace from the form submission
Trim all whitespace from every email in column A, then validate with Mailboxlayer and write syntax_valid, smtp_check, mx_found, disposable to columns B–E, and 'Keep' or 'Remove' to column F
The list has duplicates and I only want to validate unique addresses
Deduplicate column A by email address (keeping the first occurrence), then run Mailboxlayer validation and write syntax_valid, mx_found, smtp_check, disposable, and a Keep/Remove verdict to columns B–F
Emails are mixed into column A alongside phone numbers and some blank rows
Go through column A and identify only rows that contain an email address format — skip blanks and phone numbers — validate each email with Mailboxlayer, and write the verdict to column B with 'Not Email' for skipped rows
Clean the format, deduplicate, validate, and give me a summary count in one pass
Trim and lowercase every value in column A, remove duplicates, validate all remaining emails with Mailboxlayer — write syntax_valid, smtp_check, mx_found, disposable, and a Keep/Remove verdict to columns B–F, then add a summary row at the bottom counting total Keep vs Remove
The faster move is always to combine cleanup and validation in the same prompt rather than running them as separate steps.
Try It
Get the 7-day free trial of SheetXAI and open your lead gen workbook — even a messy one with mixed formatting and duplicates — and ask it to validate the full column and mark each row for import. Also check out cleaning a CRM export with Mailboxlayer or the full Mailboxlayer integration overview.