MailSlurp GraphQL Email API
MailSlurp has a powerful free GraphQL email API that lets you fetch and read emails with GraphQL in React, Apollo, iOS, Android or server to server. You can create disposable test email accounts on demand or permanent custom domains. Send and receive emails and attachments from any client that uses GraphQL.
If you are unfamiliar with GraphQL don't worry - MailSlurp has a traditional REST API and compiled SDK Clients in many languages.