You can specify what time to receive the email and on what days of the week. You will receive a separate email for each Heads Up rule you create.
By default a list will be sent, but if you click on "Calculation" you will be able to specify a summary email using operations (sum, count, average) on numeric columns (for example to display the total of the trust funds in the list).
Open the Advanced Options panel at the bottom of the form to specify how many rows to show in the email body and whether to attach a spreadsheet containing all the list results.
See updated article in Actionstep Help Center: https://support.actionstep.com/hc/en-us/articles/360000942707-Heads-Up