A valid email address is any email address that meets certain technical and formatting requirements in order to be accepted by email servers. These include email addresses that have all the necessary parts: an email prefix and a domain name, are free from syntax errors and typos, and belong to active mailboxes (i.e. not disposable emails). There are other types of email addresses, such as role-based and catch-all, that can technically accept incoming mail but may not be delivered to an actual person. These email addresses are considered risky.