Yes, Donorbox sends automated donation receipts to your donors. The receipt templates are customizable with your images and text.
Here is an example of what your receipts could look like:
You can customize your email receipt by selecting the "Email" tab of your campaign editor:
Due to delivery issues with spam filters, these emails will be sent from our email@example.com email address (some email providers have strict SPF and DKIM rules that prevent other services like Donorbox to send emails on your behalf). However, you can set the "Donor Receipt From Email" to your organization email address. This sets your organization email as the reply_to address and put your organization name as the "from" name. To do this, go to the "Receipt Email Settings" tab in your account settings, type in your email address in the appropriate text box, and click "Update":