1. 1 COP 4343 Unix System Administration Unit 14: email – send and receive mail – mail filtering – mail server – mailing lists

2. 2 Understanding Email

3. 3 Mail Transfer Agent –moves email from one server to another –new: Mail Sending Agent Mail Delivery Agent –places email in a user’s mailbox Mail User Agent –manages email for user

4. 4 Mail User Agent mail pine modern GUI-based email readers –thunderbird, mozilla mail –outlook, evolution –Kmail –WebMail

5. 5 Mail User Agent –mail –pine read email from system mailbox –/var/mail/userid send email via MTA directly

6. 6 GUI-based Mail User Agent read email from mail server via –Internet Mail Access Protocol (IMAP) –Post Office Protocol (POP3) send email to MTA via –Simple Mail Transport Protocol (SMTP) –new: authenticate/send email via MSA

7. 7 Mail Delivery Agent: procmail filters email based on user-defined criteria typical use –virus scan www.clamav.net –spam scan www.spamassassin.org

8. 8 Mail Transfer Agent sendmail Simple Mail Transport Protocol (SMTP) –TCP port 25 –new: TCP port 587 for MSA

9. 9 configuring a mail server packages –sendmail –dovecot for imap and pop3 –procmail open firewall –imap: 143, pop3: 110, smtp: 25

10. 10 sendmail configuration chkconfig sendmail on configuration directory: /etc/mail edit file: sendmail.mc dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA') LOCAL_DOMAIN(`instructor.ege.com') MASQUERADE_AS(`instructor.ege.com') install package sendmail-cf –make service sendmail start open firewall port 25

11. 11 sendmail MSA configuration convention: –users send email via their ISP possible: –allow sendmail to be RELAY –/etc/mail/access file new: sendmail configured as MSA –requires authentication –sendmail MSA port: 587

12. 12 dovecot configuration chkconfig dovecot on service dovecot start add ports 110 and 143 to iptables /etc/dovecot.conf –example setting: first_valid_uid = 500

13. 13 procmail configuration configuration –/etc/procmailrc –per user.procmailrc also define environment variables lists recipe to filter email :0 [flags] [ : [locallockfile] ]

14. 14 procmail examples :0 * ^Subject:.*scuba.* scubafile :0 * < 1000 ! myname@home :0 * ^^%! | lpr :0fw | processMailFilter

15. 15 spamassassin recipe yum install spamassassin chkconfig spamassassin on service spamassassin start /etc/procmailrc DROPPRIVS=yes :0fw | /usr/bin/spamc

16. 16 Mailing lists establish alias to send bulk email enable membership management package: mailman

17. 17 mailman configuration /etc/httpd/conf.d/mailman.conf –set domain name –restart httpd set mailman passwd –/usr/lib/mailman/bin/mmsitepass password Set the values for DEFAULT_EMAIL_HOST and DEFAULT_URL_HOST in /usr/lib/mailman/Mailman/mm_cfg.py

18. 18 mailman configuration Update Mailman list files: /usr/lib/mailman/bin/update Create a "site-wide" mailing list /usr/lib/mailman/bin/newlist mailman –you will need to add lines to /etc/aliases and then run newaliases chkconfig mailman on service mailman start visit: http://instructor.ege.com/mailman

19. 19 mailman list management select administrative interface from web page follow prompt to create new list email is sent to list administrator with instructions: –add lines to /etc/aliases file –run newaliases