An 'Opportunities Status' Report will give you an overview of the activity against your Open Opportunities so that you can identify which Opportunities haven't been touched or are likely to slip.
1. Click Reports > New Report...
2. Select Opportunities > Opportunities > Create.
3. Change Opportunity Status to Open and then define any other criteria that's appropriate for you (e.g. Close Date Range to the end of this Quarter).
4. Drag and drop the 'Days since last email' field into the Preview table.
5. Click the drop down arrow next to the 'Days since last email' column header and then click Bucket this Field....
6. Name the Bucket Field 'Last Activity' and define your Ranges (e.g. 0-14, 15-30, 31-50, 50+), then click OK.
7. Change Tabular Format to Summary.
8. Click and drag the Last Activity header and the Stage header to create a Grouping.
9. Click Add Chart and select a Vertical Bar Chart.
10. Select Stage as the Group By value.
11. Select Stacked (the middle option).
12. Click Formatting and give the Chart a Title.
13. Click Save.
14. Click Save in the top right-hand corner, complete the fields and then click Save.