ARCHIVED: What is the Simple Mail Transfer Protocol (SMTP)?
Simple Mail Transfer Protocol (SMTP) is the de facto standard for electronic mail transport across the Internet. When you send an email message, SMTP packages your message in a kind of envelope and relays it to its destination. Multiple servers are often involved in the transport of the message, and as it passes through them, each one time-stamps and tags it. Thus, when the message arrives, the recipient can get an idea of where it's been, and when it was sent. SMTP also handles error messages, sending notifications to senders when there is difficulty delivering their mail.
When you set up an email client, such as Thunderbird or Mac OS X Mail, you must specify an SMTP server for your outgoing mail. This may be different from the server you use to check incoming mail. For help setting up your email client at Indiana University, see:
Last modified on January 07, 2013.