Make a copy of the sheet and select the full block of records. Open Data → Data cleanup → Remove duplicates. Choose only the columns that define a match, and mark the header option if the first row contains column names.
01Include the whole record, then pick the matching columns
Section linkSuppose the same email appears twice but each row has a different order status. With both columns checked, the rows differ. If the goal is a single record per email, select the whole record range but use only the email column for the comparison. Decide first which record you want to retain if the other fields disagree.
02Check what the cells actually contain
Section linkGoogle says case, formatting and different formulas do not prevent a match when the values are identical. A hidden trailing space can make similar text differ. On a copy, select the affected text column and use Data → Data cleanup → Trim whitespace. That command does not remove nonbreaking spaces, which can come from pasted web text. Inspect the affected cells if they still look the same.
03Build a separate list if you need to keep the rows
Section linkPut =UNIQUE(A2:A) in a blank area to list distinct entries from column A, using a narrower range if needed. The formula leaves the source alone. Pointing it at several columns returns distinct rows across those columns. If rows still look repeated in that output, compare their underlying text or values before deleting anything from the original sheet.