Hack The Sec-Leading Resource Of Linux Tutorial: SMTP

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<span style="color: red; font-family: PT Serif, serif;"><span style="font-size: 20px; line-height: 26px;"><u><i>Install Postfix to configure SMTP server. SMTP uses 25/TCP</i></u></span></span></h5>
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<span style="color: #333333; font-family: PT Serif, serif;"><span style="font-size: 16px; font-weight: normal; line-height: 22.4px;">Postfix is a free and open-source mail transfer agent (MTA) that routes and delivers electronic mail, intended as an alternative to the widely used Sendmail MTA.</span></span></h5>
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<li><a href="http://www.hackthesec.co.in/2016/02/how-to-install-dovecot-to-configure.html" target="_blank">SMTP-Auth to use Dovecot's SASL function</a></li>
<li><a href="http://www.hackthesec.co.in/2016/02/how-to-install-dovecot-to-configure.html" target="_blank">How to Install Dovecot to configure POP/IMAP server</a></li>
</ul>
<span style="font-size: 16px; font-weight: normal; line-height: 22.4px;">Postfix is installed even if <a href="http://www.hackthesec.co.in/search/label/Centos" target="_blank">CentOS </a>system was installed with [Minimal Install], but if Postfix is not, Install it first like follows.</span></span></h5>
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<pre style="background: rgb(54, 54, 54); border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-stretch: inherit; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline;"><span style="color: lime; font-family: Monaco, Courier New, DejaVu Sans Mono, Bitstream Vera Sans Mono, monospace; font-size: medium;"><span style="line-height: 19px; white-space: pre-wrap;">[root@mail ~]# yum -y install postfix</span></span></pre>
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtUFqbeQIjF1sMQ24NxFVepEZtUi97GyhdDw5rkJdnjhF2GdWUUl5ZA18_KoVGGvv_b4dN8X3dSOJGnIlPXERtkXRkSjXeiMlc17UuWMGn2CfqyNvQNVgHOiYxC1CJg5BA_ddr1QZ6Nr32/s1600/Postfix_architecture_www.hackthesec.co.in.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="292" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjtUFqbeQIjF1sMQ24NxFVepEZtUi97GyhdDw5rkJdnjhF2GdWUUl5ZA18_KoVGGvv_b4dN8X3dSOJGnIlPXERtkXRkSjXeiMlc17UuWMGn2CfqyNvQNVgHOiYxC1CJg5BA_ddr1QZ6Nr32/s640/Postfix_architecture_www.hackthesec.co.in.png" width="640" /></a></div>
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Postfix Configuration.<br /></div>
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<pre style="background-attachment: initial; background-clip: initial; background-color: #363636; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; border-image-outset: initial; border-image-repeat: initial; border-image-slice: initial; border-image-source: initial; border-image-width: initial; border-radius: 7px; border: 1px solid rgb(221, 221, 221); font-stretch: inherit; margin-bottom: 15px; margin-top: 15px; overflow-x: auto; overflow-y: hidden; padding: 18px 20px; vertical-align: baseline;"><span style="font-family: Monaco, Courier New, DejaVu Sans Mono, Bitstream Vera Sans Mono, monospace; font-size: medium;"><span style="line-height: 19px; white-space: pre-wrap;"><span style="color: white;">[root@mail ~]# </span><span style="color: lime;">vi /etc/postfix/main.cf</span><span style="color: white;">

# line 75: uncomment and specify hostname
myhostname = mail.hackthesec.co.in

# line 83: uncomment and specify domain name
mydomain = </span></span></span><span style="color: white; font-family: Monaco, 'Courier New', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', monospace; font-size: medium; line-height: 19px; white-space: pre-wrap;">hackthesec.co.in</span><span style="color: white; font-family: Monaco, Courier New, DejaVu Sans Mono, Bitstream Vera Sans Mono, monospace; font-size: medium;"><span style="line-height: 19px; white-space: pre-wrap;">
</span></span><span style="font-family: Monaco, Courier New, DejaVu Sans Mono, Bitstream Vera Sans Mono, monospace; font-size: medium;"><span style="line-height: 19px; white-space: pre-wrap;"><span style="color: white;">
# line 99: uncomment
</span><span style="color: orange;">myorigin = $mydomain
</span><span style="color: white;">
# line 116: change
inet_interfaces = all

# line 164: add
</span><span style="color: orange;">mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
</span><span style="color: white;">
# line 264: uncomment and specify your local network
mynetworks = 127.0.0.0/8, 10.0.0.0/24

# line 419: uncomment (use Maildir)
home_mailbox = Maildir/

# line 574: add
</span><span style="color: orange;">smtpd_banner = $myhostname ESMTP
</span><span style="color: white;">
# add follows to the end
# limit an email size for 10M
message_size_limit = 10485760
# limit a mailbox for 1G
mailbox_size_limit = 1073741824

# for SMTP-Auth
</span><span style="color: orange;">smtpd_sasl_type = dovecot
</span><span style="color: white;">smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
</span><span style="color: orange;">smtpd_sasl_security_options = noanonymous
</span><span style="color: white;">smtpd_sasl_local_domain = $myhostname
</span><span style="color: orange;">smtpd_recipient_restrictions = permit_mynetworks,permit_auth_destination,permit_sasl_authenticated,reject</span></span></span></pre>
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[root@mail ~]# systemctl </span><span style="color: lime;">restart postfix</span><span style="color: white;"> 
[root@mail ~]# </span><span style="color: lime;">systemctl </span><span style="color: white;">enable postfix </span></span></span></pre>
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Install and Configure Postfix to configure SMTP server

Install Postfix to configure SMTP server. SMTP uses 25/TCP Postfix is a free and open-source mail transfer agent (MTA) that routes and d...