Donorbox has a feature to flag donors that want to subscribe to your mailing list. This is necessary because one cannot spam donors with unwanted emails. It may even upset them and possibly prevent them from contributing further.
To set up your Donorbox form to get permission to add donors to your mailing, follow these steps:
Log in to your Dashboard and click the Edit button on the campaign form you want to modify, as shown.
On the next page, click on the edit button of the section "Receipt Email":
You need to scroll down, and you will see a Toggle button, labeled "Ask donor to subscribe to our mailing list". Click it to turn this feature on.
Once you enable this option, you can customize the label to whatever you'd like it to display. You may also choose to have this option already selected by default in your donation form.
Finally, once you finish editing this section, click on "Update", and all changes will be applied:
The form will then display this option, as shown.
Now, whenever you want to check who subscribed to your mailing list, you need to go to your Donations page, and you need to download a CSV file by clicking on Export:
Once you download the file, you'll find the following column where you can confirm who subscribed: