Mail

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Sendmail

Installation 

sudo apt-get install sendmail

Configuration for using SMTP server 

sudo nano /etc/mail/sendmail.mc

At the end, add below below 2 line between existing 1st & 4th Line: 

MAILER(`local')dnl
MAILER_DEFINITIONS
define('SMART_HOST',`smtp.gmail.com')
MAILER(`smtp')dnl

Now reconfigure sendmail to use above config: 

sudo bash -c 'cd /etc/mail/ && m4 sendmail.mc >sendmail.cf'
sudo service sendmail restart

Troubleshooting

If you are unable to send emails, check below log file: 

sudo cat /var/log/mail.err

If you get this error: 

My unqualified host name (test-ubuntu) unknown; sleeping for retrytest-ubuntu

Edit hosts file to add below entries 

sudo nano /etc/hosts
127.0.0.1       localhost.localdomain test-ubuntu

Authentication

Make auth subdirectory in mail config directory: 

cd /etc/mail
mkdir auth
chmod 700 auth

Create a file with your auth information to the smtp server 

cd auth
touch client-info

In the file, put the following, matching up to your smtp server: 

AuthInfo:mail.domain.com "U:root" "I:username" "P:password"

Generate the Authentication database, make both files readable only by root 

makemap hash client-info < client-info
chmod 600 client-info
cd ..

Add the following lines to sendmail.mc. Make sure you update your smtp server 

 MAILER_DEFINITIONS

 FEATURE(`authinfo',`hash /etc/mail/auth/client-info.db')dnl
 MAILER(`local')dnl
 MAILER_DEFINITIONS
 define(`SMART_HOST',`mail.domain.com')dnl
 define(`confAUTH_MECHANISMS', `EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN')dnl
 MAILER(`smtp')dnl

Invoke creation sendmail.cf 

sudo sendmailconfig

Test Mail: 

sendmail -t myaddress@gmail.com -v -i < body.txt

Testing

Manual Testing using Telnet

Connect to the server 

telnet 127.0.0.1 25

If you see similar to below lines, you are connected to the server: 

220 test-ubuntu ESMTP Sendmail 8.15.2/8.15.2/Debian-3; Wed, 2 Aug 2017 13:45:29 +0530; (No UCE/UBE) logging access from: localhost(OK)-localhost [127.0.0.1]

Issue below commands/Inputs one by one to send a test mail: 

HELO server

MAIL from:amanjosan2008@gmail.com

RCPT to: amandeep.singh@citrix.com

DATA
Subject:Test mail
hello amandeep.singh@citrix.com from amanjosan2008@gmail.com
This is the body
.

If you see this output, your mail is queued to be send: 

250 2.0.0 v7289CNJ007111 Message accepted for delivery

Exit the program: 

quit
Testing using CLI

Create a sample body file 

nano body.txt

Paste below text into it: 

Subject: test mail to Some Address!
From: Me <fromaddress@somemail.com>
To: Vasya<toaddress@somemail.com>
first line of my message

Send email using below command: 

/usr/sbin/sendmail -t -f myaddress@gmail.com -v -i < body.txt

PHP Mail

COnfigure PH to use Sendmail: 

/etc/php5/apache2/php.ini:

Add at the end of this file: 

; For Unix only.  You may supply arguments as well (default: "sendmail -t -i").
; http://php.net/sendmail-path
sendmail_path = "/usr/sbin/sendmail -t -f myaddress@gmail.com -i"

Restart Apache server: 

sudo service apache2 restart
PHP Script to send mail

Create a PHP file in the root Directory: 

sudo nano /var/www/html/mail.php

Paste and save the below contents in it: 

<?php
$to = "amandeep.singh@test.com";
$subject = "Alert Mail";
$txt = "This is an Alert Mail";
$headers = "From: Alert@test.com" . "\r\n" .
"CC: testuser@test.com";

mail($to,$subject,$txt,$headers);
?>

Your mail should be sent after you open below link in browser: 

http://10.107.88.68/mail.php

SendEmail

Source: caspian.dotconf.net

Installation using apt: 

sudo apt-get install sendemail

Manual Installation: 

wget http://caspian.dotconf.net/menu/Software/SendEmail/sendEmail-v1.56.tar.gz
tar -zxvf /tmp/sendEmail-v1.56.tar.gz
cd sendEmail-v1.56/
sudo cp -a sendEmail /usr/local/bin/
chmod +x /usr/local/bin/sendEmail

Testing: 

sendEmail

Sending Email with inline attachment: 

nano body.txt

<html>
<img src="logo.png" alt="logo" align="right" height="40" width="120"/>
<p>Hi,</p>
<p>This is a test Alert Mail.</p>
<p>Please find below the details about this Alert:<br /><br /></p>
<p>There are the details.</p>
</html>

sendEmail -f codered@domain.com -t amandeep.singh@domain.com -s mail.domain.com -u "Codered Test Mail" -o message-file=/home/test/body.txt -o message-content-type=html -a ~/logo.png

Misc

Figure out SMTP address

  • Windows:

Open CMD.exe and type below commands: 

nslookup
set type=MX
domain.name
  • Linux:
dig domain.name MX




References





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