Hi John,
Thanks for your detailed question. It is helpful in really understanding the ultimate goal here. I have been trying to think of different ways that this can be achieved as a current solution and the only way I can think of is to create a custom SSRS report. This could get messy and the report could run into timeout issues depending on how many leads you have.
I'm not sure if you thought about possibly changing your process so that it makes reporting a little easier. For instance, how are you generating the email to the Sale Rep when a lead comes in? Is this done using CRM or some custom application?
A easier solution could alter CRM to use workflows. So when Lead is created trigger a workflow. This workflow would then do an if conditional check to see IF Lead Source (essentially a field that identifies where the lead came from) = Web, Then the workflow proceed with the following:
1. Update Lead record status to Initial Contact. This would be a picklist field to help track the status of the Lead record.
2. Send email to sales rep
3. Create email with a standard template. Note this is not a Send Email step but a create email step. This would allow the sales rep to customize the email
4. Wait until Email in Step 3 status = sent
5. Update Lead record status to Initial Contact made
Then you can create a simple report within CRM that can show you which Leads have a "record status" of initial contact.
There are different ways you could handle this but if you are looking to find a solution with how the system is configured now, you may need to engage a partner to help build a custom SSRS report.
Hope this helps!