MailChimp provideds an excellent guide to cleaning email lists (removing duplicates and bounces) with Microsoft Excel when utilizing email marketing lists in marketing research.
MailChimp was originally built for companies that already have a list management system, but needed help with delivery. Since we clean your bounces for you in the list area, only those who clean an internal database manually would need to use these instructions.
Instructions for removing duplicates from your list:
- Open up Microsoft Excel.
- Paste your entire list into Column A.
- Sort the entire column alphabetically (A > Z). This is very important.
- Click on and highlight Column B.
- With Column B highlighted (press the gray B button above the column to highlight the entire column), enter the following into the “formula” box in Excel: =IF(TRIM(A1)=TRIM(A2),”",TRIM(A1))

View the entire Cleaning your list with Microsoft Excel procedure.









