This search is of Transactions and we want the email to come from the Sales Rep for each transaction

You can make it look like the email is coming from the Sales rep by pasting in the field ID for the Sales rep as well as the ID for the sales rep email. I have a similar search email alert set up for new POs that make it look like it's coming from the buyer. We have it set up like this (see screenshot).

OK that may work, I will give it a try. Thank you for the suggestion!

I tested this with a scheduled search just now, and it does work as long as "summarize scheduled emails" box is unchecked. It won't work for summarized scheduled emails.