A brief tutorial on the SMTP protocol

SMTP, or Simple Mail Transfer Protocol, describes the mechanism by which e-mail is transferred from a user’s local e-mail client to their mail server, and from there to the recipient’s mail server. Final delivery to the recipient’s mail client is typically handled by the unrelated POP3 or IMAP protocols. In this tutorial, we describe how to use a telnet client to send e-mail to our fake SMTP server by manually stepping through a typical SMTP session.

Introducing our Fake SMTP Server

We are pleased to announce the release of SMTP Bucket, a fake SMTP server for e-mail integration testing. In this post, we explain what the service is, why we created it, and explore some of the technologies that power it. We then go on to speculate about how it might evolve in the future.