So I have a column filled with email addresses, and I need to count the number of unique values in this column, as long as the date hasn't changed in another column. Once the date changes, then I need to reset the count. I have a formula that works for counting the number of unique text values, but I have to hardcode the section of the column of email addresses to check. This is not homework, so don't say I haven't tried anything, this is for my job, just don't haven't used Excel too much.

Any help would be greatly appreciated.