Form Builder - Something to note - Form Builder might not be as focused as the other two apps for this but does have other functions also.
Shopify also has a document with some information on Phishing/ protecting your account which isn't exactly about Spam emails but worth the read and to have. You can see it by clicking here.
All the best, Nick
Nick | Community Moderator @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog