Hi! I'm a SF Nonprofit Cloud User. I'm trying to build out a Lapsed Donor Report. I'm having trouble obtaining BOTH the last transaction info as well as contact info, most importantly email. Can anyone help mix the contact and transaction info?

It would be difficult to include both the Transaction and the Contact objects in the same report type. However, an easy solution could be simply creating a Contacts with Opportunities (donations) report to find the last transaction date. Or perhaps you could try creating a joined report, with one report containing the Transaction object.