How to use Exim4 to Send Email from Beaglebone Black Debian

I’ve recently gotten Exim4 to send mail from the BBB with Debian, using the Gmail SMTP server. (I tried using the BBB as the server with SMTP port 25, but my ISP [Comcast] blocks that port to prevent spam.) I am running code to monitor a sensor, and wanted an email alert to me at certain detected values. Here are the general steps:

  1. Tell Google that you’ll be sending email from your BBB. From a browser on the BBB, sign in to your gmail account at:

  2. Open port 587. For this you need to be root. Check your iptables (firewall) first to see if 587 is already open:


iptables -L -n


If not, then


iptables -A OUTPUT -p tcp --dport 587 -j ACCEPT


and, if you don’t have any input rules, which is good (see, then

# iptables -I INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

3. Install and configure exim4 as root. This is the package that sends the email. 

# apt-get install exim4

Now, configure exim as root:

# dpkg-reconfigure exim4-config

in the dialog, answer as follows:

> Configuration type |  mail sent by smarthost; received via SMTP or fetchmail |
> - | - |
>  System mail name |  localhost |
>  IP-addresses to listen on for incoming SMTP connections | ; ::1 (to refuse external connections) |
> Other destinations for which mail is accepted | *leave empty* |
> Machines to relay mail for | *leave empty* |
> IP address or host name of the outgoing smarthost | |
> Hide local mail name in outgoing mail ? | yes |
> Keep number of DNS-queries minimal (Dial-on-Demand) ? | no |
> Delivery method for local mail | mbox format in /var/mail/ |
> Split configuration into small files ? | no<br> |

check /etc/exim4/update-exim4.conf.conf to see if the file looks like the below, and if not, change it:
dc_local_interfaces=' ; ::1'

Then modify /etc/exim4/passwd.client to (substitute your gmail name and pwd):

Change permissions, etc

# chown root:Debian-exim /etc/exim4/passwd.client
# chmod 640 /etc/exim4/passwd.client

restart Exim

If you only want to send mail, install mutt....
With mutt u can use any SMTP server, and mutt comes with its own;-)

I’m trying to get mutt running to get error messages from crontab. I installed mutt with aptitude and it may be working but I don’t know how to set it up to get the messages :-[

Apr 20 23:49:01 beaglebone /USR/SBIN/CRON[8657]: (root) CMD (export DISPLAY=:0 && /usr/bin/python /home/debian/Desktop/
Apr 20 23:50:01 beaglebone /USR/SBIN/CRON[8690]: (root) CMD (export DISPLAY=:0 && /usr/bin/python /home/debian/Desktop/
Apr 20 23:51:02 beaglebone /USR/SBIN/CRON[8723]: (root) CMD (export DISPLAY=:0 && /usr/bin/python /home/debian/Desktop/
Apr 20 23:52:01 beaglebone /USR/SBIN/CRON[8756]: (root) CMD (export DISPLAY=:0 && /usr/bin/python /home/debian/Desktop/

Setup is described in says there is a muttrc file in “a user’s $HOME directory” but I find only unreadable muttrc files elsewhere and I’m not sure I know where and what a “user’s $HOME directory” is.

  1. Do I need to set up some directory in /home/?
  2. Do I need to create a muttrc file to configure mutt?
  3. Is there a way to find and read the sent messages?


Create the file .muttrc eg in /root/ or in /home/debian/ (the user
that wants to use mutt....) and add a line
set smtp_url="smtp://"
And don't forget the return after this line. (as in crontab as well)

* * * * * root ls /somefolder | mutt -s "" 2>&1

BTW: didn't you read my Email where i worte that you can redirect
crontabs output into a file:
* * * * * root ls /somefolder >> /root/crontab_err.txt 2>&1