E-mail Servers

AIT is responsible for the design, installation, and oversight of Penn State's primary incoming and outgoing e-mail servers, which processes millions of e-mail transactions each day.

Incoming E-mail Servers

email.psu.edu and mail.psu.edu

Penn State's primary incoming servers email.psu.edu and mail.psu.edu use the Post Office Protocol (POP) to hold users' e-mail until downloaded through an e-mail client. Similar to the way in which the post office holds and processes surface mail, the POP server retains e-mail until it can be delivered to users' respective e-mail addresses.

Outgoing E-mail Server


Penn State's primary outgoing mail server is smtp.psu.edu. SMTP (Simple Mail Transfer Protocol) is the protocol used to send e-mail messages between servers. E-mail sent from any mail client with its outgoing server configured for smtp.psu.edu is sent to this server. Then, the smtp server routes the mail to its destination for users to retrieve messages via a client configured for a POP or IMAP server. Because incoming and outgoing servers work in tandem, e-mail clients must be configured for both servers in order to work properly.

The SMTP server accepts an enormous amount of e-mail each day. To ensure that only valid Penn State e-mail is sent, individuals who use a third-party ISP to check their Penn State POP mail must first check mail before attempting to send mail through smtp.psu.edu. E-mail that is sent without first successfully checking for new e-mail on the server will be rejected. Those who use Penn State's network through outlets such as computer labs, residence hall wireless or ethernet connections, authsmtp or via the VPN are not affected by this.


Authenticated SMTP allows users who connect via a third-party internet connection to use Penn State's outgoing e-mail server. The authenticated version of smtp.psu.edu, which is authsmtp.psu.edu, requires a user to enter his/her password before being permitted to send messages. The new server authenticates senders of outbound mail to protect the mail server from abuse from e-mail-related viruses and spammers. Note that you can use POP before SMTP to check your e-mail before you send it. Instructions for configuring the various e-mail clients are found at: http://kb.its.psu.edu/article/1308

Secure E-mail Transactions

Secure Socket Layer (SSL) Connections

All students, faculty, and staff who use ITS' POP or IMAP e-mail services must check e-mail via a secure-only SSL connection. SSL is a type of software that encrypts individual userids and passwords when users check e-mail via mail.psu.edu or email.psu.edu. The SSL changes are part of Penn State's on-going security effort to make e-mail correspondence at the University safer. University community members were given advance notification so that they could change settings in e-mail clients accordingly. Secure methods such as Kerberized POP and Penn State WebMail are still valid and secure options for checking e-mail; KPOP users or users Penn State WebMail were and are encouraged to continue with those options.

Internet Message Access Protocol (IMAP)

IMAP was developed at the University of Washington. IMAP requires an SSL connection, provides a method for accessing electronic mail that is stored on a mail server. It permits an e-mail client, such as Thunderbird, to access remote messages (both new and saved) and stores them as if they were local. For example, e-mail stored on an IMAP server may be manipulated from your computer at home, your computer at the office, or from a laptop while traveling without the need to transfer messages back and forth between computers. IMAP can only be used with mail.psu.edu. IMAP allows for the use of a Kerberos ticket as an addtional method for authentication as well as a username and password. IMAP is a service available to faculty, staff and students. An IMAP account may be obtained at https://www.work.psu.edu/access/email/

Post Office Protocol (POP)
POP remains a widely utilized protocol for email retrieval. For POP configurations, please visit The Penn State Knowledge Base Kerberized Post Office Protocol (KPOP)

Kerberos is a network authentication protocol. It is designed to provide strong authentication for client/server applications by using public-key cryptography. It is often supported in Telnet, FTP and e-mail applications. At Penn State, KPOP, which is supported on email.psu.edu and mail.psu.edu and is opt-in. In addition to SSL, KPOP and WebMail provide users with secure alternatives for checking mail.