Excel 2007 : advanced unique list

I have 3 columns of email addresses (A:C). there are repeats in all 3 columns sporadically. I have a work around by putting the following in coumn d: =IF(A1<>"",A1,";") for the first 30 rows with A1 increasing with each row. Then B1...C1...for 30 rows each also in column D. I then copy as values to column F, sort and advanced filter (check unique)... Does anyone have a formula to do it faster? Thanks in advance for any help.