<\/span><\/h2>\nThe COUNTIF function is one of the most useful methods for identifying duplicate emails.<\/p>\n
Assume the email addresses are in column A and the first email is in cell A2.<\/p>\n
In another column, enter:<\/p>\n
=COUNTIF($A:$A,A2)<\/code><\/p>\nThe formula counts how many times the email address in A2 appears throughout column A.<\/p>\n
If the result is:<\/p>\n
1<\/p>\n
the address appears once.<\/p>\n
If the result is:<\/p>\n
2<\/p>\n
the address appears twice.<\/p>\n
If the result is:<\/p>\n
3<\/p>\n
the address appears three times.<\/p>\n
For example:<\/p>\n
Email | Count<\/p>\n
john@example.com<\/a> | 2
\nmary@example.com<\/a> | 1
\ndavid@example.com<\/a> | 3<\/p>\nThis makes it easy to identify repeated addresses.<\/p>\n
You can then filter the Count column to show only numbers greater than 1.<\/p>\n
This gives you a list of all email addresses that occur more than once.<\/p>\n
<\/span>Method 3: Label Emails as Duplicate or Unique<\/span><\/h2>\n