How To Use Gmail Account To Relay Email From a Shell Prompt

Posted on in Categories Backup, Debian Linux, fedora linux, Howto, Linux, Linux desktop, RedHat/Fedora Linux, Tip of the day last updated April 5, 2009

Usually, you do not need to setup an email server under Linux desktop operating system. Most GUI email clients (such as Thunderbird) supports Gmail POP3 and IMAP configurations. But, how do you send mail via the standard or /usr/bin/mail user agents or a shell script? Programs such as sendmail / postfix / exim can be configured as a gmail smarthost but they are largely overkill for this use.

You can use gmail as a smart host to send all messages from your Linux / UNIX desktop systems. You need to use a simple program called ssmtp. It accepts a mail stream on standard input with recipients specified on the command line and synchronously forwards the message to the mail transfer agent of a mailhub for the mailhub MTA to process. Failed messages are placed in dead.letter in the sender’s home directory.

Install ssmtp

Type the following command under CentOS / RHEL / Red Hat / Fedora Linux:
# yum install ssmtp
Type the following command under Debian / Ubuntu Linux:
# apt-get update && apt-get install ssmtp

Configure gmail as a smarthost

Open /etc/ssmtp/ssmtp.conf, enter:
# vi /etc/ssmtp/ssmtp.conf
Update file with the following settings:

AuthUser=[email protected]
AuthPass=Your-Gmail-Password
FromLineOverride=YES
mailhub=smtp.gmail.com:587
UseSTARTTLS=YES

Also, make sure you disable Sendmail:
# service sendmail stop
# chkconfig sendmail off
# mkdir /root/.bakup
# mv /usr/sbin/sendmail /root/.bakup
# ln -s /usr/local/ssmtp/sbin/ssmtp /usr/sbin/sendmail
Now, you can use mail / mailx command to send email messages. You can also write a shell script to backup your files and email to somewhere else (see below). You can test settings using following syntax:
$ echo "This is a test" | mail -s "Test" [email protected]

A note about sSMTP

sSMTP works well for desktop systems, but it is not a replacement for Sendmail / Postfix / Exim / Qmail for email server environment. This software is perfect for a single user system.

Further readings:

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

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60 comment

  3. Thanks for the info. Today I was searching for a way out for logwatch to send email via using external SMTP without installing sendmail or other MTA in my cache server and then after an hour I got this solution. Thanks

    Reply Report comment

  4. hi, thanks for the wonderful tip..
    i went through the conf file…….but i m stuck somewhere in between…

    #
# Config file for sSMTP sendmail
#
# The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
root=postmaster

# The place where the mail goes. The actual machine name is required no
# MX records are consulted. Commonly mailhosts are named mail.domain.com
mailhub=mail

# Where will the mail seem to come from?
#rewriteDomain=

# The full hostname
hostname=sanzle-desktop

# Are users allowed to set their own From: address?
# YES - Allow the user to specify their own From: address
# NO - Use the system generated From: address
#FromLineOverride=YES

    should i update this file adding the lines you hav provided..and what abt the disabling Sendmail…I can find those mentioned lines..

    Thanks in advance.

    Reply Report comment

  7. Hello !
    thanks for sharing your knowledge.
    I am using Ubuntu 8.04.
    when i opened .conf file i got the following script:

    #
    # Config file for sSMTP sendmail
    #
    # The person who gets all mail for userids < 1000
    # Make this empty to disable rewriting.
    root=postmaster

    # The place where the mail goes. The actual machine name is required no
    # MX records are consulted. Commonly mailhosts are named mail.domain.com
    mailhub=mail

    # Where will the mail seem to come from?
    #rewriteDomain=

    # The full hostname
    hostname=nee-pc

    # Are users allowed to set their own From: address?
    # YES – Allow the user to specify their own From: address
    # NO – Use the system generated From: address
    #FromLineOverride=YES
    ~
    ~
    Now how to update this file with tha changes you provided??
    pls tell me!
    thanka in advance!

    Reply Report comment

  21. HI , i made the above configurations as stated but when i a m sending mail to test then the following error is being showed:
    /usr/sbin/sendmail: No such file or directory
    “/root/dead.letter” 9/232
    . . . message not sent.
    please help

    Reply Report comment

  24. Awesome .. exactly what I needed for the machines at home .. I refuse to use my ISP’s unauthenticated mail server, mostly because it’s a bit of a blackhole.. and I’ve been moving away from using mail on my hosted servers … most stuff has been ported to gmail servers.

    Thanks for the quick and easy fix to using gmail as my smarthost!

    Reply Report comment

  25. Dear Sir/ Madam,
    Recently I have configured sandmail on Linux RH 9, and capable to send and receive mail from outlook express. But problem is domain name show diffenence in outlook express Inbox , that is : but I have configured domain name “bgdnyk.com” on linux send mail server.
    Could you please asists, how can I get accurate domain name in outlook express.

    Reply Report comment

  27. TO: Sergio Montini
    [Ideally, I would like a script to email me my system logs (cron, login, etc)]

    Here is a line of code that may help. It was pulled from Linux Pro Magazine August2009 issue, page 61. You should be able to add it to your backup script that cron launches. You’ll probably need to tweak it to suit your needs and not copy it verbatim, but this is the basic idea. Rather than sending the list of files in a backup directory, you could also send the contents of a log file.

    ls -l /my-backups/’date +%y-%m-%d’ | mail -s “daily backup report” [email protected]

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  29. I Got this error? Any help ? Pleaseeeeee

    $ echo “This is a test” | mail -s “Test” [email protected]
    -su: $: command not found
    Null message body; hope that’s ok
    mail: /usr/sbin/sendmail: No such file or directory
    Can’t send mail: sendmail process failed with error code 1

    Thanks

    Reply Report comment

  30. also :

    ls -latr /usr/sbin/ | grep mail
    -rwxr-sr-x 1 root mail 81304 2008-12-30 21:34 imapd*
    lrwxrwxrwx 1 root root 5 2010-03-23 16:36 mailq -> ssmtp*
    lrwxrwxrwx 1 root root 27 2010-03-23 16:40 sendmail -> /usr/local/ssmtp/sbin/ssmtp

    Reply Report comment

  33. There is some parts missing for CentOS 5:
    ssmtp is available in the epel repository, that needs to be added before “yum install ssmtp”

    The softlink is a bit off:
    ln -s /usr/sbin/ssmtp /usr/sbin/sendmail

    And I love this article, made my day 😉

    Reply Report comment

  35. As always, Thanks Vivek.

    For the sake of others wondering.
    # vim /etc/ssmtp/ssmtp.conf
    # service sendmail stop
    # chkconfig sendmail off
    # mkdir /root/.backup
    # mv /usr/sbin/sendmail /root/.backup/
    # whereis ssmtp
    ssmtp: /usr/sbin/ssmtp /etc/ssmtp /usr/share/man/man8/ssmtp.8.gz
    # ln -s /usr/sbin/ssmtp /usr/sbin/sendmail
    # echo “This is a test email” | mail -s “Test” [email protected]

    Used it for my nagios email notification for repl

    Reply Report comment

  36. I have tried above mentioned configured on my system. It worked nicely for a day but now it shows me following error.
    “SSL_connect: Connection reset by peer. send-mail: Cannot open smtp.gmail.com:587”

    Please get me to resolve this issue.

    Reply Report comment

  37. for those who has problems like this:

    Null message body; hope that’s ok
    mail: /usr/sbin/sendmail: No such file or directory
    Can’t send mail: sendmail process failed with error code 1

    try this:

    the manual says that we must create a symlink:

    ln -s /usr/local/ssmtp/sbin/ssmtp /usr/sbin/sendmail

    but, depends on ur distro or version the correct location of this directories. In my case I use Fedora 12-64 and find that “/usr/local/ssmtp/sbin/ssmtp” is “/usr/sbin/ssmtp”, why:

    [[email protected] ssmtp]# whereis ssmtp
    ssmtp: /usr/sbin/ssmtp /etc/ssmtp /usr/share/man/man8/ssmtp.8.gz

    so I change the link to ” ln -s /usr/sbin/ssmtp /usr/sbin/sendmail ”

    and now is working, any doubts or comments Ill be glad to help you.

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  48. [[email protected] /]# yum install ssmtp
    Loaded plugins: fastestmirror
    Loading mirror speeds from cached hostfile
    * addons: centos.excellmedia.net
    * base: centos.excellmedia.net
    * extras: centos.excellmedia.net
    * updates: centos.excellmedia.net
    Setting up Install Process
    No package ssmtp available.
    Nothing to do

    WHY THIS KOLAVERI DI?

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  53. One of the main reasons this method won’t work is that the ssmtp command may be located on a different directory. This is the updated version of the command lines in order to disable send mail:
    # service sendmail stop
    # chkconfig sendmail off
    # mkdir /root/.bakup
    # mv /usr/sbin/sendmail /root/.bakup
    # ln -s $(which ssmtp) /usr/sbin/sendmail

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