Excel and Monkeys

I've been building my email list recently and found too many duplicate email addresses on several different "lists.txt" i've gathered in the span of say... ten years. For my first attempt at contacting our previous clients, I tried mailchimp and found excellent for managing and building lists and sending beautiful html pages! Previously i was sending Thunderbird created ones and it was a very difficult thing to do!




As I was importing my list to MailChimp (Powered by MailChimp) I found my excel lists to be unbearable. I never thought organizing an email list could be this TEDIOUS! I've spend two whole days just looking for duplicates and makign sure to filter out the spam emails like viagra@boost.com or the countless number of qwert@gmail.com type of emails. I thought i had culled it down to a manageable 1000 but as i run this find duplicate script in excel my list was reduced to a not very encouraging 500.

here's a link to Microsoft's very own guide to find duplicates on excel!

Method 1: Use a worksheet formula

To use a worksheet formula to compare the data in two columns, follow these steps:

1.	Start Excel.
2.	In a new worksheet, enter the following data (leave column B empty): A1: 1 B1: C1: 3 A2: 2 B2: C2: 5 A3: 3 B3: C3: 8 A4: 4 B4: C4: 2 A5: 5 B5: C5: 0
3.	Type the following formula in cell B1: =IF(ISERROR(MATCH(A1,$C$1:$C$5,0)),"",A1)

How to compare data in two columns to find duplicates in Excel