So, I've been working on this brain tickler for over nine hours, and I guess I just lack the experience to plug all the pieces together myself.

If anyone feels like lending a helping hand, it would be infinitely appreciated.

I'm trying to accomplish several different things, across multiple sheets - all at the same time and in a single, repeatable formula.

Each sheet has several thousand entries of personnel data (Name, Surname, Purchase ID#s, mod dates, etc), but I'm choosing to sort by email address for ease, and then just importing data from across the rest of the row correspondingly.

These are the goals:

1) Import all non-repeat entries from Sheet2 to Sheet3. I would just copy/paste and go by hand, but I need this particular article to be dynamic and there's already a LOT of data to sift.
2) If ((the email in Sheet1!E1 is NOT present in Sheet2!C1:C-Any) && (Email is not already present in Sheet 3)), place the item in Sheet3:C1.
3) If #2 is FALSE, proceed to checking Sheet1!E2 WITHOUT advancing from Sheet3!C1.
4) Repeat until #2 is TRUE or no valid values remain in Sheet1.

Preferably, I would also like to make the data sortable, but the sorting functions gets hinky really fast and I'm not 100% sure it's entirely feasible.

What I've got right now looks like:

=IF( AND( MATCH(Sheet1!E1, Sheet2!C1:C2001), MATCH(Sheet2!E1, Sheet2!E1:E2001)), Sheet1:A1)

As you can see, this fails on just about every front:

a) It completely ignores #1
b) It fails to cover a theoretically infinitely deep column Sheet1!E / Sheet2!C.
c) It simply produces a "FALSE" value in the event of #3/4, rather than advancing its search.

Like I said, I'm a bit out of my depth on this one.

I'll keep plugging away, but if anyone could help me solve any of the puzzle I would be so very grateful.

Thanks.