1. P.O.P. A presentation brought to you by Thomas

2. Topics Introduction General Information Area of use Functionality The alternative way POP3 vs. IMAP Conclusion

3. What is POP Post Office Protocol Actual Version is POP3 Responsible for recieving emails from a mailserver Most widely implemented protocol for retrieval of Internet Mail

4. General information Standard Port for POP3 is 110 Session – Layer Platform independent RFC 1939 Email service provider need to install a POP3 server for offering POP. POP3 transferred emails are secured by SSL or TLS

5. Area of use Supported by most mail client applications TCP/IP Networks Free internet mail services -...but mostly IMAP is provided on a higher service level

6. How does it work XXX@YYY.ZZ -XXX indicates the user who is registered at the webdomain YYY.ZZ -The user logs in to the webdomain via email client. Password and account will be checked. -If validation is correct, POP3 of the client requests download of new mails.

7. How does it work II POPserver of mail provider accepts the request, if there are no problems. Download will be initialized by mail client application. All mails could be deleted from the mailbox on mailserver. (optional) After download connection will be closed again.

8. For the one without mail client... Via telnet direct connection to mailbox using POP (PlainTextLogin). Commands: USER Login LIST shows the content of mailbox RETR downloads selected mail DELE deletes selected mail QUIT Closes connection from hostside

9. telnet pop.gmx.net 110 Trying 213.165.65.60... Connected to pop.gmx.net. Escape character is ‚^C]'. +OK GMX POP3 StreamProxy ready USER cartman666@gmx.de +OK May I have your password, please? +OK mailbox has 3 messages (5985 octets) Login procedure

10. LIST +OK mailbox has 3 messages (5985 octets) 1 1845 2 2616 3 1524. RETR 1 +OK message follows Return-Path: X-Flags: 0000 Delivered-To: GMX delivery to cartman666@gmx.de... (MAIL) checkmail procedure

11. ...(MAIL END) DELE 1 +OK message deleted QUIT +OK bye Connection closed by foreign host. Delete/Logout procedure

12. POP3 vs. IMAP IMAP is suitable for online access to a mailbox service, where messages are stored and filed on a permanent or semi-permanent basis on the server. POP3 is suitable for a mailbox service, where messages are only stored for a temporary period on the server. POP3 is less complex. Generally IMAP is used in companies, POP is used by private email users.

13. Conclusion Everyone who plans to implement an email system should think about using IMAP or POP3, depending on his needs. Easy and fast working. For private use adequate, but companies with bigger mailing systems should use IMAP.

14. Thank you for your attention......any questions?