Sending mail from a Bash shell script

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

Answer 1

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 2

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 3

Send mail from Bash with one line:

echo "your mail body" | mail -s "your subject" yourmail@yourdomain.com -a "From: sender@senderdomain.com"

Answer 4

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 5

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 6

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".