This will depend on the Form plugin that you’re using. Early versions of BoldGrid included NinjaForms. The newer version of BoldGrid includes WPForms. If you are using NinjaForms, you will need to click on Forms, click on edit the form that you’re trying to use, then select Email and Actions. Here you will see the email forms that are being used. You need to find the one that is being used and click on EDIT. The action name should be EMAIL and the type should be email. Make sure that email address is active where you host your email and that it is correctly spelled. Once you’re sure everything is correct, click on the SAVE button.
For the WPForms, you’ll need to go into the actual form and edit it. Then click on Settings and then Notifications. You’ll see the email address set there. The email account must be a valid account for URL you are using for WordPress.