Okay, I have opened this on a windows machine using excel 2013. This is what I have tried and failed so far, still.

1. copy =IFERROR(INDEX(B:B,SMALL(IF(ISNA(MATCH(B$2:B$9,A$2:A$5,0)),ROW(B$2:B$9)),ROWS(C$2:C2))),"") to clipboard

2. click on the C2 cell and click CTRL+SHIFT+ENTER.

3. Nothing happens

2nd attempt.

1. Copy

2. Paste in C2 and then drag copy down. The first cell has an email in it, but the rest of the C cells don't show anything. If I click on a cell it will show me the formula but nothing shows up

What am I doing wrong? It feel like I am simply not clicking the right button or cell . . .