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10.5: Send mail from Terminal using mail/sendmail UNIX
I have some scripts that need to send mail from the command line. While mail works out of the box, it will not work if your ISP blocks port 25, or if your ISP's network address range is on a blacklist. You could use and AppleScript, but that requires that the user in question be logged in, and may not work for scripts run by root.

This solution configures postfix, the service used by mail and sendmail, to relay messages through a third-party server (ideally your ISP), optionally using authentication and TLS. You'll need to be root to create/edit the files and run the commands. So, without further delay, enjoy.

Edit /etc/postfix/ and add the following to the end:
relayhost = # (you can use, such as
smtp_sasl_auth_enable = yes
smtp_use_tls = yes
smtp_enforce_tls = yes
smtp_sasl_security_options =
smtp_sasl_tls_security_options =
smtp_sasl_tls_verified_security_options =
smtp_tls_loglevel = 2 # optional if you wan to see what's going on with the TLS negotiation in /var/log/mail.log
smtp_sasl_password_maps = hash:/etc/postfix/smtp_sasl_passwords
smtp_tls_per_site = hash:/etc/postfix/smtp_tls_sites
tls_random_source = dev:/dev/urandom
Create /etc/postfix/smtp_sasl_passwords with the following contents: username:password
Create /etc/postfix/smtp_tls_sites with the following contents: MUST_NOPEERMATCH
Then run the following commands:
$ cd /etc/postfix
$ chmod go-rx smtp_sasl_passwords
$ postmap smtp_sasl_passwords
$ postmap smtp_tls_sites
To test, try:
echo "Hello" | mail -s "Test"
The above test may not work if your provider requires a valid source e-mail address. If that's the case, try:
printf "Subject: TestnHello" | sendmail -f
This second test form specifies the "from" address as you, but can be changed to anything you want as long as it passes muster with your provider's server. You can now check the logs:
tail /var/log/mail.log
Or, if you're crafty, you'll open a second Terminal window, and before running the tests in the first window, do:
tail -f /var/log/mail.log
Here are some notes about options that you see in the content above:
  • The *_security_options settings allow postfix to use plain text passwords during authentication (albeit over TLS).
  • The MUST_NOPEERMATCH in the smtp_tls_sites file ignores certificate mismatches when negotiating TLS. This, overall, is not a good idea, but I didn't have time to play with it yet and configure the CA. Other options are NONE, MAY, and MUST, but some will require configuration of the CA so that a trust can be established with the server. This, I believe, is configured with smtp_tls_CAfile. When I get it working, I may post an update.
  • The chmod go-rx smtp_sasl_passwords removes the group and other/world read/execute permissions on the password files. Only the root user should be able to read it.
That is all. I pieced this information together from lots of useless searches and several useful how-to's and postings. I make no guarantees, but I hope it helps someone.
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10.5: Send mail from Terminal using mail/sendmail
Authored by: ars on Dec 22, '08 03:44:50PM

I tried this with two authenticated accounts I have and I got an error in both cases:status=deferred (host said: 454 5.7.3 Client does not have permission to Send As this sender. (in reply to end of DATA command))
I tried both tests and both gave the above error, so I don't know what went wrong.

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10.5: Send mail from Terminal using mail/sendmail
Authored by: macintown on Dec 23, '08 03:17:36AM

For Mac OS X Server you can just send mail using above mentioned commands without any extra configuration.

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10.5: Send mail from Terminal using mail/sendmail
Authored by: boysoprano on Dec 23, '08 09:38:23AM

Thanks, this works great! Only problem is the sender field appear as "Machine Username <>", not "Full Name <>". Does anyone know how to change this? The only way I could find to customize the display name was to change my user account name in System Preferences :/

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10.5: Send mail from Terminal using mail/sendmail
Authored by: techiejohn on Jan 01, '09 06:46:09AM
You can fix the sender using the following:
printf "From: Sender Name <>\nTo:\nSubject: Subject\n\nBody\n" | /usr/sbin/sendmail -F "Sender Name" -f "" ""

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10.5: Send mail from Terminal using mail/sendmail
Authored by: Pedro Estarque on Dec 23, '08 09:13:20PM
Or use SendEmail, a simple perl script that has all the options you can think of and won't mess with your default installation.

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10.5: Send mail from Terminal using mail/sendmail
Authored by: techiejohn on Jan 01, '09 06:53:44AM

Here's the update for the SSL certificate verification:

If you want the verification process to work, you'll need to provide valid certificate authority (CA) certificates to OpenSSL via postfix. For some reason, my computer did not have the default OpenSSL root CA certificates installed. So, I decided to import them from the system root CA keychain.

Run the following:

security find-certificate -a -p /System/Library/Keychains/SystemRootCertificates.keychain > /System/Library/OpenSSL/certs/cert.pem

Include the following in /etc/postfix/

smtp_tls_CAfile = /System/Library/OpenSSL/certs/cert.pem

Now you can change the MUST_NOPEERMATCH to just MUST, and the certificate verification should succeed if the certificate was signed with one of the system-accepted root certificates.

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For those Terminally Challenged
Authored by: gatorparrots on Jan 06, '09 07:08:32PM
This hint may well be beyond the capabilities of many readers. For those with a desire to replicate the goal of this hint, it can be done with some free/inexpensive software: MailServe (Leopard) [$15] MailServe (Tiger) [Free] Postfix Enabler (Tiger & Panther) [Free]

Or you could splurge and get a copy of OS X Server and use Server Admin to enable your own mail server...

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10.5: Send mail from Terminal using mail/sendmail
Authored by: anton on May 02, '11 03:01:18PM
I found this hint very useful and wanted to illustrate its use based on the example of gmail as your outgoing SMTP server. Here is the content of my file:

smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_use_tls = yes
smtp_tls_CAfile = /System/Library/OpenSSL/certs/cert.pem

As you can see I didn't use parameter, which appears to be not required for gmail.

smtp_tls_per_site = hash:/etc/postfix/smtp_tls_sites

The content of /etc/postfix/sasl_passwd file is

[]:587 password

after you create the file issue

sudo chmod 400 /etc/postfix/sasl_passwd
sudo postmap /etc/postfix/sasl_passwd

Generate the certificate (this was copied from post above)

sudo security find-certificate -a -p /System/Library/Keychains/SystemRootCertificates.keychain > /System/Library/OpenSSL/certs/cert.pem

Finally restart Postfix for good measure

sudo Postfix stop
sudo Postfix start

Thats it. You can now send email though gmail.

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