mailserver . -
TRANSCRIPT
Mail Server Setup using Sendmail
on CentOS 5.8
Jeong Chul
tland12.wordpress.com
Computer Science
ITC and RUPP in Cambodia
Mail Server Setup using Sendmail
on CentOS 5.8 Part 1 • Step 1 Email Service
• Step 2 Essential Email Operation
• Step 3 Package installation and Startup
• Step 4 Sendmail Configuration – 1, 2
Part 2 • Step 5 Inbound Sendmail Aliases
• Step 6 Sendmail.cf file
• Step 7 Sendmail Operation
• Step 8 IMAP and POP3 on Dovecot
• Step 9 MUA Configuration
Mail Server Testing Environment
1.sever.chul.com: 192.168.80.25
Sendmail Mail server (mail.chul.com)
Evolution for MUA
2.client.chul.com: 192.168.80.10
Linux mail client
Thunderbird for MUA
3.Windows 7 : 192.168.80.1
Windows mail client
Outlook 2010 for MUA
Step 1 Email Service E-mail System Components
1.Mail User Agent (MUA):
A client used to compose and read e-mail (Outlook, Evolution, Thunderbird,
Mutt)
2.Mail Transfer Agent (MTA):
An SMTP server used to relay or accept e-mail for delivery (Postfix, Sendmail,
Exim, Qmail, Exchange server)
3.Mail Delivery Agent (MDA):
A program used by the final MTA to deliver e-mail to the message store
May be included with the MTA or a separate program such as procmail
4.Mail Access Agent (MAA):
An IMAP/POP3 server used by an MUA to access the message store (Dovecot,
Cyrus IMAP)
Step 3 Installation and startup
1.Package installation sendmail-cf-8.13.8-8.1.el5_7 sendmail-doc-8.13.8-8.1.el5_7 sendmail-8.13.8-8.1.el5_7 sendmail-devel-8.13.8-8.1.el5_7
2. Service startup and main directory # service sendmail start # ls –l /etc/mail/ 3. Service startup checking # ps –ef | grep sendmail # netstat –nat | grep 25 4. Runlevel registration # chkconfig sendmail on # chkconfig –list sendmail 5. Testing on command # telnet localhost 25 # mail –v –s ‘title’ [email protected] < /etc/passwd
Step 4 Sendmail Configuration (1)
1.Introduction to Sendmail Configuration /etc/mail/sendmail.mc and /etc/mail/sendmail.cf # m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf "dnl " at the start of a line is a comment in /etc/mail/sendmail.mc
2. # service sendmail restart automatically builds configuration files Converts /etc/mail/sendmail.mc into /etc/mail/sendmail.cf
3. Incoming Sendmail configuration /etc/mail/sendmail.mc dnl dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl /etc/mail/local-host-names ① mail.chul.com ② chul.com ③ jeong.net
Add a line for each domain/host for which we accept local delivery
Step 4 Sendmail Configuration (2)
4. Outgoing Sendmail configuration To relay e-mail sent by hosts on your internal network dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA') dnl /etc/mail/access : each internal network or host for which the server will relay Connect:192.168.80 RELAY Connect:127.0.0.1 RELAY Connect: chul.com RELAY Connect: spam.net REJECT To: [email protected] ERROR:550 bad name From: [email protected] REJECT
5. Sendmail: Masquerading in /etc/mail/sendmail.mc EXPOSED_USER(`root')dnl MASQUERADE_AS(`chul.com')dnl FEATURE(masquerade_envelope)dnl FEATURE(masquerade_entire_domain)dnl MASQUERADE_DOMAIN(chul.com)dnl
# service sendmail restart
Step 5 Inbound Sendmail Aliases
1.Local aliases: /etc/aliases ◄ Local mail forwarding fakename: realname
root: tland,linux,song,park,jeong
staff: :include /home/staff/staff_list ◄Mailing List
2. Virtual aliases: /etc/mail/virtusertable
[email protected] user1
[email protected] user2
[email protected] [email protected]
@abc.com [email protected]
@dom1.org %[email protected] //same user different
domain
Step 6 Sendmail.cf file 1. Name for error message DnMAILER-DAEMON //if want, change
2. Version Number for security DZ8.13.8 O SmtpGreetingMessage=$j Sendmail $v/$Z; $b // j: hostname v&Z: version b: timestamp
3. Max Message Size (byte) O MaxMessageSize=2048000 //2 Mb
4. Max hop Count O MaxHopCount=17 // Max mail server for routing
5. Queue directory for sending and receiving temporarily O QueueDirectory=/var/spool/mqueue
6. Minimum time in queue before retry O MinQueueAge=30m
Step 7 Sendmail Operation
1./etc/mail/local-host-names must contain server's name and aliases
2.# mail -v user view SMTP exchange with local relay
3.# mailq and mailq -Ac view messages queued for future delivery
4.# sendmail –q reprocess the email queue
5.# tail -f /var/log/maillog view log in real-time
Step 8 IMAP and POP3 on Dovecot
1.Dovecot supports POP3, POP3s, IMAP, andIMAPs 2. Installation and startup # yum install dovecot # vi /etc/dovecot.conf protocols = imap imaps pop3 pop3s # service dovecot start 3.Service startup checking # ps –ef | grep dovecot # netstat –nat | grep 110,143 4. Runlevel registration # chkconfig dovecot on # chkconfig –list dovecot 5. Testing on command # telnet localhost 110 //pop3 # telnet localhost 143 //imap
Step 9 MUA Configuration
1.Graphical:
Evolution on Sever system
# yum install evolution
Thunderbird on Client system of Linux
# yum install thunderbird
Outlook 2010 on Client system of Windows 7
2.Text-mode: Mutt and Fetchmail mutt -f pop://user@server
mutt -f pops://user@server