You can send acknowledgements to people who have signed up to make a regular donations or payments to your organisation as follows
Web Widget Setup
Go into Settings and find Web Widgets - you will see under the Transaction Settings that you can choose the acknowledgement you want to send by email or mail for Transactions and Recurring Payment Instructions.
If a donor provides an email address and the widget has an email acknowledgement set up that acknowledgement will be used - otherwise any mail acknowledgement will be used.
If the widget does not have an email acknowledgement set up then any mail acknowledgement will be used.
Sending the Acknowledgements
Under Actions | Acknowledgements you can download or email the acknowledgements.