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Use Case

Cleaning up email lists in CSV format

Remove duplicates, fix formatting, and prep lists for campaign tools.

Jan 2, 20255 min read
A dirty email list tanks deliverability. Duplicates, typos, and invalid addresses hurt your sender reputation and waste money.

Find and remove duplicates

Sort by email address and scan for repeats. Decide which record to keep when duplicates have different associated data.

  • Sort by email to cluster duplicates
  • Keep the most recent or most complete record
  • Document your deduplication logic

Spot obvious invalids

Search for common typos: gmial, outlok, missing TLDs. These will hard bounce and hurt your reputation.

  • Search for common domain typos
  • Look for missing @ symbols
  • Check for incomplete addresses

Quick CTA

Clean your email list

Sort and search to find duplicates and typos instantly.

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Standardize formatting

Email addresses should be lowercase and trimmed. Extra spaces and inconsistent casing cause matching issues.

  • Convert all to lowercase
  • Trim leading and trailing spaces
  • Remove any invisible characters

Verify before sending

After cleaning, verify the list size makes sense. A big drop might indicate over-aggressive cleaning.

  • Compare before and after row counts
  • Spot check removed records
  • Run through validation service if available

Key takeaway

List hygiene is ongoing. Clean before every campaign to protect deliverability.