Sending mail from a Bash shell script - macos

Question

I am writing a Bash shell script for Mac that sends an email notification by opening an automator application that sends email out with the default mail account in Mail.app. The automator application also attaches a text file that the script has written to. The problems with this solution are
It is visible in the GUI when sending
It steals focus if Mail is not the current application
It is dependent on Mail.app's account setup being valid in the future
I figure to get around those shortcomings I should send the mail directly from the script by entering SMTP settings, address to send to, etc. directly in the script. The catch is I would like to deploy this script on multiple computers (10.5 and 10.6) without enabling Postfix on the computer. Is it possible to do this in the script so it will run on a base Mac OS X install of 10.5. and 10.6?
Update: I've found the -bs option for Sendmail which seems to be what I need, but I'm at a loss of how to specify settings.
Also, to clarify, the reason I'd like to specify SMTP settings is that mails from localhost on port 25 sent out via Postfix would be blocked by most corporate firewalls, but if I specify the server and an alternate port I won't run into that problem.

Answer 1

Since Mac OS X includes Python, consider using a Python script instead of a Bash script. I haven't tested the sending portion, but it follows the standard example.
Python script
# Settings
SMTP_SERVER = 'mail.myisp.com'
SMTP_PORT = 25
SMTP_USERNAME = 'myusername'
SMTP_PASSWORD = '$uper$ecret'
SMTP_FROM = 'sender#example.com'
SMTP_TO = 'recipient#example.com'
TEXT_FILENAME = '/script/output/my_attachment.txt'
MESSAGE = """This is the message
to be sent to the client.
"""
# Now construct the message
import smtplib, email
from email import encoders
import os
msg = email.MIMEMultipart.MIMEMultipart()
body = email.MIMEText.MIMEText(MESSAGE)
attachment = email.MIMEBase.MIMEBase('text', 'plain')
attachment.set_payload(open(TEXT_FILENAME).read())
attachment.add_header('Content-Disposition', 'attachment', filename=os.path.basename(TEXT_FILENAME))
encoders.encode_base64(attachment)
msg.attach(body)
msg.attach(attachment)
msg.add_header('From', SMTP_FROM)
msg.add_header('To', SMTP_TO)
# Now send the message
mailer = smtplib.SMTP(SMTP_SERVER, SMTP_PORT)
# EDIT: mailer is already connected
# mailer.connect()
mailer.login(SMTP_USERNAME, SMTP_PASSWORD)
mailer.sendmail(SMTP_FROM, [SMTP_TO], msg.as_string())
mailer.close()
I hope this helps.

Answer 2

Actually, "mail" works just as well.
mail -s "subject line" name#address.ext < filename
works perfectly fine, as long as you have SMTP set up on your machine. I think that most Macs do, by default.
If you don't have SMTP, then the only thing you're going to be able to do is go through Mail.app. An ALTERNATIVE way to go through mail.app is via AppleScript. When you tell Mail.app to send mail via AppleScript you can tell it to not pop up any windows... (this does still require Mail.app to be configured).
Introduction to Scripting Mail has a good description of how to work with mail in AppleScript.

Answer 3

There is a program called Sendmail.
You probably don't want to use the -bs command unless you are sending it as raw SMTP like Martin's example. -bs is for running an SMTP server as a deamon. Sendmail will send directly to the receiving mail server (on port 25) unless you override it in the configuration file. You can specify the configuration file by the -C paramter.
In the configuration, you can specify a relay server (any mail server or sendmail running -bs on another machine)
Using a properly configured relay server is good idea because when IT manages mail servers they implement SPF and domain keys. That keeps your mail out of the junk bin.
If port 25 is blocked you are left with two options.
Use the corporate SMTP server.
Run sendmail -bd on a machine outside of
the corporate firewall that listens
on a port other than 25.
I believe you can add configuration parameters on the command line. What you want is the SMART_HOST option. So call Sendmail like sendmail -OSMART_HOST=nameofhost.com.

Answer 4

Probably the only way you could do this, while keeping the program self-sufficient, is if you have direct access to an SMTP server from the clients.
If you do have direct access to an SMTP server you can use the SMTP example from wikipedia and turn it into something like this:
#!/bin/bash
telnet smtp.example.org 25 <<_EOF
HELO relay.example.org
MAIL FROM:<joe#example.org>
RCPT TO:<jane#example.org>
DATA
From: Joe <joe#example.org>
To: Jane <jane#example.org>
Subject: Hello
Hello, world!
.
QUIT
_EOF
To handle errors I would redirect the output from telnet to a file and then grep that for a "success message" later. I am not sure what format the message should be, but I see something like "250 2.0.0 Ok: queued as D86A226C574" in the output from my SMTP server. This would make me grep for "^250.*queued as".

Answer 5

Send mail from Bash with one line:
echo "your mail body" | mail -s "your subject" yourmail#yourdomain.com -a "From: sender#senderdomain.com"

Answer 6

sendEmail is a script that you can use to send email from the command line using more complicated settings, including connecting to a remote smtp server:
http://caspian.dotconf.net/menu/Software/SendEmail/
On OSX it is easily installable via macports:
http://sendemail.darwinports.com/
Below is the help page for the command, take note of the -s, -xu, -xp flags:
Synopsis: sendEmail -f ADDRESS [options]
Required:
-f ADDRESS from (sender) email address
* At least one recipient required via -t, -cc, or -bcc
* Message body required via -m, STDIN, or -o message-file=FILE
Common:
-t ADDRESS [ADDR ...] to email address(es)
-u SUBJECT message subject
-m MESSAGE message body
-s SERVER[:PORT] smtp mail relay, default is localhost:25
Optional:
-a FILE [FILE ...] file attachment(s)
-cc ADDRESS [ADDR ...] cc email address(es)
-bcc ADDRESS [ADDR ...] bcc email address(es)
Paranormal:
-xu USERNAME authentication user (for SMTP authentication)
-xp PASSWORD authentication password (for SMTP authentication)
-l LOGFILE log to the specified file
-v verbosity, use multiple times for greater effect
-q be quiet (no stdout output)
-o NAME=VALUE see extended help topic "misc" for details
Help:
--help TOPIC The following extended help topics are available:
addressing explain addressing and related options
message explain message body input and related options
misc explain -xu, -xp, and others
networking explain -s, etc
output explain logging and other output options

Answer 7

I whipped this up for the challenge. If you remove the call to 'dig' to obtain the mail relay, it is a 100% native Bash script.
#!/bin/bash
MAIL_FROM="sfinktah#bash.spamtrak.org"
RCPT_TO="sfinktah#bash.spamtrak.org"
MESSAGE=message.txt
SMTP_PORT=25
SMTP_DOMAIN=${RCPT_TO##*#}
index=1
while read PRIORITY RELAY
do
RELAY[$index]=$RELAY
((index++))
done < <( dig +short MX $SMTP_DOMAIN )
RELAY_COUNT=${#RELAY[#]}
SMTP_COMMANDS=( "HELO $HOSTNAME" "MAIL FROM: <$MAIL_FROM>" "RCPT TO: <$RCPT_TO>" "DATA" "." "QUIT" )
SMTP_REPLY=([25]=OK [50]=FAIL [51]=FAIL [52]=FAIL [53]=FAIL [54]=FAIL [55]=FAIL [45]=WAIT [35]=DATA [22]=SENT)
for (( i = 1 ; i < RELAY_COUNT ; i++ ))
do
SMTP_HOST="${RELAY[$i]}"
echo "Trying relay [$i]: $SMTP_HOST..."
exec 5<>/dev/tcp/$SMTP_HOST/$SMTP_PORT
read HELO <&5
echo GOT: $HELO
for COMMAND_ORDER in 0 1 2 3 4 5 6 7
do
OUT=${SMTP_COMMANDS[COMMAND_ORDER]}
echo SENDING: $OUT
echo -e "$OUT\r" >&5
read -r REPLY <&5
echo REPLY: $REPLY
# CODE=($REPLY)
CODE=${REPLY:0:2}
ACTION=${SMTP_REPLY[CODE]}
case $ACTION in
WAIT ) echo Temporarily Fail
break
;;
FAIL ) echo Failed
break
;;
OK ) ;;
SENT ) exit 0
;;
DATA ) echo Sending Message: $MESSAGE
cat $MESSAGE >&5
echo -e "\r" >&5
;;
* ) echo Unknown SMTP code $CODE
exit 2
esac
done
done

Answer 8

Here is a simple Ruby script to do this. Ruby ships on the Mac OS X versions you mentioned.
Replace all the bits marked 'replace'. If it fails, it returns a non-zero exit code and a Ruby back trace.
require 'net/smtp'
SMTPHOST = 'replace.yoursmtpserver.example.com'
FROM = '"Your Email" <youremail#replace.example.com>'
def send(to, subject, message)
body = <<EOF
From: #{FROM}
To: #{to}
Subject: #{subject}
#{message}
EOF
Net::SMTP.start(SMTPHOST) do |smtp|
smtp.send_message body, FROM, to
end
end
send('someemail#replace.example.com', 'testing', 'This is a message!')
You can embed this in a Bash script like so:
ruby << EOF
... script here ...
EOF
For some other ways to send Ruby emails, see Stack Overflow question How do I send mail from a Ruby program?.
You can use other languages that ship with Mac OS X as well:
How do I send email with Perl?
Sending HTML email using Python

Answer 9

1) Why not configure postfix to handle outbound mail only and relay it via a mail gateway? Its biggest advantage is that it is already installed on OS X clients.
2) Install and configure one of the lightweight MTAs that handle only outbound mail, like nullmailer or ssmtp (available via MacPorts).
In both cases use mailx(1) (or mutt if you want to get fancy) to send the mails from a shell script.
There are several questions on Server Fault that go into the details.

Answer 10

sendmail and even postfix may be too big to install if all you want to do is to send a few emails from your scripts.
If you have a Gmail account for example, you can use Google's servers to send email using SMTP. If you don't want to use gGoogle's server, as long as you have access to some SMTP server, it should work.
A very lightweight program that makes it easy to do so is msmtp. They have examples of configuration files in their documentation.
The easiest way to do it would be to set up a system-wide default:
account default
host smtp.gmail.com
from john.doe#gmail.com
user john.doe#gmail.com
password XXX
port 587
msmtp should be very easy to install. In fact, there is a port for it, so it could be as easy as port install msmtp.
After installing and configuring msmtp, you can send email to john.doe#gmail.com using:
mail -s <subject> john.doe#gmail.com <<EOF
<mail text, as many lines as you want. Shell variables will be expanded>.
EOF
You can put the above in a script. See man mail for details.

Answer 11

Here's a modified shells script snip I've used on various UNIX systems...
(echo "${MESSAGE}" | ${uuencode} ${ATTACHMENT}$basename ${ATTACHMENT}) | ${mailx} -s "${SUBJECT}" "${TO_LIST}"
uuencode and mailx are set to the executables. The other variables are from user input parsed using getopts.
This does work but I have to admit more often than not I use a simple Java program to send console emails.

Answer 12

Try mtcmail. Its a fairly complete email sender, completely standalone.