comparing cells in mail merge

Hi, I have an Excel spreadsheet that I want to perform a mail merge with. The problem is that if there are entries with the same address I want to send only one document to that address. So I started a new spreadsheet and have been trying to do an if statement that compares the addresses and if they're the same, copy the first name, last name, address, etc. For example I have

A. B. C. D. E. F
Bob, Jones, 6 Main St., City, State, Zip
Sue, Jones, 6 Main St., City, State, Zip
Harry, Smith, 3 Carpenter, City, State, Zip
Betty, Edwards, 2 Campbell Ave, City, State, Zip

if(c1=c2,a1) and so on

I would like the new spreadsheet to include Bob and Sue because they have the same address but not Harry or Betty.

Bob, Sue, Jones, 6 Main St., City, Stat, Zip

Is this possible? I might be a bit over my head with this project!

Thank you, Glenn,I'm new to this!

I'll attach the spreadsheet and a copy of the letter.
I want to compare the address and if it's the same send the attached letter. If they're not the same, skip
that row and compare the next two rows.