9 mail/mailx command examples to send emails from command line on Linux

By | June 5, 2020

Send mails from command line

The mail command is an essential one that should be available on any linux server so that various services and other web applications can generate and transmit emails.

In a previous post on mail command we saw how the mail command can be used to send emails from the command line on your linux server.

In this tutorial we shall be using an enhanced version of the mail command. Its called mailx (or just mail when installed), and it can do many more things than what the older mail command from gnu mailutils package can do.

How does it work

The mail/mailx command needs a local smtp server (MTA) running in order to deliver the emails. THe route taken by the email is somewhat like this -

mail -> sendmail -> local MTA -> recipient MTA [Inbox]

The recipient MTA would be gmail's smtp server if your recipient is someone at gmail.com for instance. For the local MTA, you need to install an smtp server like Postfix. A basic installation of Postfix with minimal configuration would work in most cases.

Install the mailx command

On Ubuntu/Debian based systems the mailx command is available from 2 different packages -

1. heirloom-mailx
2. bsd-mailx

We shall be using the heirloom-mailx package because it has more features and options.
On CentOS/Fedora based systems, there is only one package named "mailx" which is the heirloom package.

To find out what mailx package is installed on your system, check the "man mailx" output and scroll down to the end and you should see some useful information.

# ubuntu/debian
$ sudo apt-get install heirloom-mailx

# fedora/centos
$ sudo yum install mailx

Using the mailx command

Once installed, the mailx command can be directly referenced with the name mail, so you just type in that in the command line.

1. Simple mail

Run the following command, and then mailx would wait for you to enter the message of the email. You can hit enter for new lines. When done typing the message, press Ctrl+D and mailx would display EOT.

After than mailx automatically delivers the email to the destination.

$ mail -s "This is the subject" [email protected]
Hi someone
How are you
I am fine

2. Take message from a file

The message body of the email can be taken from a file as well.

$ mail -s "This is Subject" [email protected] < /path/to/file

The message can also be piped using the echo command -

$ echo "This is message body" | mail -s "This is Subject" [email protected]

3. Multiple recipients

To send the mail to multiple recipients, specify all the emails separated by a comma

$ echo "This is message body" | mail -s "This is Subject" [email protected],[email protected]

4. CC and BCC

The "-c" and "-b" options can be used to add CC and BCC addresses respectively.

$ echo "This is message body" | mail -s "This is Subject" -c [email protected] [email protected]

5. Specify From name and address

To specify a "FROM" name and address, use the "-r" option. The name should be followed by the address wrapped in "<>".

$ echo "This is message body" | mail -s "This is Subject" -r "Harry<[email protected]>" [email protected]

6. Specify "Reply-To" address

The reply to address is set with the internal option variable "replyto" using the "-S" option.

# replyto email
$ echo "This is message" | mail -s "Testing replyto" -S replyto="[email protected]" [email protected]

# replyto email with a name
$ echo "This is message" | mail -s "Testing replyto" -S replyto="Mark<[email protected]>" [email protected]

7. Attachments

Attachments can be added with the "-a" option.

$ echo "This is message body" | mail -s "This is Subject" -r "Harry<[email protected]>" -a /path/to/file [email protected]

8. Use external SMTP server

This is an exclusive feature, that you get only with heirloom mailx and not bsd mailx, or the mail command from gnu mailutils or the mutt command.

The mailx command can use an external smtp server to use to relay the message forward. The syntax is a bit lengthy but makes sense.

$ echo "This is the message body and contains the message" | mailx -v -r "[email protected]" -s "This is the subject" -S smtp="mail.example.com:587" -S smtp-use-starttls -S smtp-auth=login -S smtp-auth-user="[email protected]" -S smtp-auth-password="abc123" -S ssl-verify=ignore [email protected]

Here is a breakdown

$ echo "This is the message body and contains the message" | mailx -v \
> -r "[email protected]" \
> -s "This is the subject" \
> -S smtp="mail.example.com:587" \
> -S smtp-use-starttls \
> -S smtp-auth=login \
> -S smtp-auth-user="[email protected]" \
> -S smtp-auth-password="abc123" \
> -S ssl-verify=ignore \
> [email protected]

You can use the gmail smtp servers and send emails via your gmail account. That is so cool!
For gmail specifically you would need to enable less secure apps settings before you can send mail like that.

9. Verbose - watch smtp communication

When using external smtp servers, you can choose to watch the entire smtp communication that is done in the background. This is useful specially when testing or debugging smtp servers.

$ echo "This is the message body and contains the message from heirloom mailx" | mailx -v -s "This is the subject" -S smtp="smtp.gmail.com:587" -S smtp-use-starttls -S smtp-auth=login -S smtp-auth-user="[email protected]" -S smtp-auth-password="mypassword" -S ssl-verify=ignore [email protected]
Resolving host smtp.gmail.com . . . done.
Connecting to . . . connected.
220 mx.google.com ESMTP je4sm32812877pbd.94 - gsmtp
>>> EHLO enlightened
250-mx.google.com at your service, []
250-SIZE 35882577
220 2.0.0 Ready to start TLS
>>> EHLO enlightened
250-mx.google.com at your service, []
250-SIZE 35882577
334 VXNlcmU6
>>> YmnbWFpbC5jb20=
334 UGFzcmQ6
>>> KnJgzKg==
235 2.7.0 Accepted
>>> MAIL FROM:<enlightened@enlightened>
250 2.1.0 OK je4sm32812877pbd.94 - gsmtp
>>> RCPT TO:<[email protected]>
250 2.1.5 OK je4sm32812877pbd.94 - gsmtp
>>> DATA
354  Go ahead je4sm32812877pbd.94 - gsmtp
>>> .
250 2.0.0 OK 1417930703 je4sm32812877pbd.94 - gsmtp
>>> QUIT
221 2.0.0 closing connection je4sm32812877pbd.94 - gsmtp


In case the mails are not being delivered properly you need to check a few things. The first thing to check is that an smtp server (mta) is running locally. The netstat command can tell that

$ sudo netstat -ltnp | grep 25
[sudo] password for enlightened: 
tcp        0      0    *               LISTEN      2541/master     
tcp6       0      0 :::25                   :::*                    LISTEN      2541/master

If an stmp server like Postfix is running and still mails are not going, then try re-configuring Postfix for example. On Ubuntu/Debian systems, this can be done with the dpkg-reconfigure command

$ sudo dpkg-reconfigure postfix

Then retry, the mail command and it should work. If it still doesn't, try contacting your server provider.

No mails from local systems

If you try to send mails from your local computer to a gmail address, your mail would most likely be rejected, so don't try doing that.

This is because ordinary computers connected to internet address have an ip address that is not associated with any valid domain as such, and gmail strictly verifies such credentials before approving any mail to go through.

Notes and Resources

Apart from mailx, there are other tools like Swaks and smtp-cli that can be used to send mails from command line and support various features like specifying smtp servers and adding attachments and so on.

However the mailx command is available in the default repositories of most common distros, so can be installed easily. Further it maintains a syntax very similar to that of the mail command which makes it a drop in replacement for the older mail command.

The mailx command is even capable of reading mails from remote IMAP servers, but that is something we kept out of this post and would talk later. To learn more check the man page for the mailx command with "man mailx".

About Silver Moon

A Tech Enthusiast, Blogger, Linux Fan and a Software Developer. Writes about Computer hardware, Linux and Open Source software and coding in Python, Php and Javascript. He can be reached at [email protected].


9 mail/mailx command examples to send emails from command line on Linux
  1. mano

    might be worth pointing out that most of this won’t work on a lot of systems,
    illegal option — S
    illegal option — a
    illegal option — r

  2. Dave

    You don’t detail how mailx determines the smtp envelope from address
    >>> MAIL FROM:
    Obviously it’s user@hostname, but how can this be over-ridden with mailx ?

  3. John Smith

    I want my printer to send emails to external email addresses like Gmail.com, I setup the ubuntu server as explained and set the ubuntu server as the smtp server on printer. I can send emails from ubuntu server to gmail, but it’s not relaying emails to gmail.com from the printer itself. What should I do? Please help.

  4. Selva

    Hi Team,

    I would like to know, whether we have option to send the attachment with password protected through mailx UNIX command? can anyone help me on this.

  5. Henrik

    Hi Silver Moon

    Great article!

    I have a cron job like this:
    tar -czf /home/backup/myfolder/myfile_$(/bin/date +\%Y\%m\%d).tgz /home/public_html -X /home/backup/myfile-exclude.txt

    I have edit my cron job to this:
    tar -czf /home/backup/myfolder/myfile_$(/bin/date +\%Y\%m\%d).tgz /home/public_html -X /home/backup/myfile-exclude.txt | mail -s “Cron Daemon: mywebsite.com – files backup” support@mydomain

    Normally the Cron job puts some info into the Body, but how do I get this to work? I have tried with:
    < /dev/null




  6. Abhishek

    I am using attachment command in phone script but it is not working whether if the same command runing on emulator



    I have followd your “tuto” ( use Centos7 )

    I still have this error ?? can you help me ?

    Connecting to . . . connected.

    220 smtp3.tech.numericable.fr ESMTP Postfix
    >>> EHLO centos7
    250-SIZE 10240000
    250 8BITMIME
    >>> AUTH LOGIN
    503 5.5.1 Error: authentication not enabled
    smtp-server: 503 5.5.1 Error: authentication not enabled

    my mailrc file ;
    #set smtp-use-starttls
    set nss-config-dir=~/.mozilla/firefox/yyyyyyyy.default/
    set ssl-verify=ignore
    set smtpd_sasl_auth_enable
    # set smtp
    set smtp=smtp://smtp.numericable.fr:25
    set [email protected]
    # tell mailx that it needs to authorise
    set smtp-auth=login
    # set the user for SMTP
    # set [email protected]
    set [email protected]
    # set the password for authorisation
    set smtp-auth-password=xxxxxx

  8. Mark Dean

    Good info. Just to clarify, sendmail/postfix/etc are MTAs and either relay through an smtp relay or directly communicates to the destination smtp servers, depending on how the MTA is configured. So the flow would be mail_client > mta > smtp_relay OR destination_smtp_server > recipient’s inbox. So using common programs as an example: mailx > postfix > smtp.yourorg.com > smtp.gmail.com > [email protected] inbox. A common example where this configuration is used is Linux servers that need to send to external email recipients (alerts and stuff). In that case, you configure the Linux server to use your outgoing smtp server via sendmail or postfix or other MTA to relay the email by allowing the IP of the Linux server to relay through the smtp server.

  9. Hans

    Thank you for your post. Can I use Mailx for send up to 15000 mails ? I’m searching a alternative to online newsletter service (payment)!

    1. Jas

      Yes, you can use Mailx or any other scripts to send any volume of emails provided that your domain SMTP relay is capable to handle volume. Do you run your own mail server or using one of the shared hosting? If you run yours … yes you could send any volume but may take few hours to send. You can’t send out emails just using home computer as those will not be delivered to end users or will directly go in users Spam folder. If you need to use home computer … you would need to hop / forward your emails to your domain SMTP relay of “from user” to send the emails to users. Reach-out if you need professional help for setting up mail server to handle your newsletter … you would need one dedicated public IPAddress on a Linux server. I am assuming that these are registered users for business and you are authorized to send them newsletter.

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