Yes, er4hu324372834.42web.io can receive emails.
No, er4hu324372834.42web.io is a throwaway domain and should be blocked.
You can use MailCheck's free API to automatically block throwaway emails. Read our documentation to get started. No registration required.
A record
185.27.134.94
MX record
mail.mailinator.com
23.239.11.30