Mail testing
MailPit
Mailpit is packed full of features for developers wanting to test SMTP and emails. It acts as an SMTP server, provides a modern web interface to view & test intercepted emails. It also contains an API for automated integration testing.
MailHog
Web and API based SMTP testing. MailHog is an email testing tool for developers. It is written in Go and distributed as a single binary. It is a mail server that intercepts and stores emails sent by applications during development and testing. You can view the emails in a web interface or retrieve them with the JSON API.