Skip to main content

Distributing your outgoing mails from Multiple IP addresses

Some mail providers like hotmail, yahoo restrict the number of connections from a single IP and the number of mails that can be delivered in an hour from a single IP. To increase your ability to deliver large number of genuine emails from your users to such sites, you may want to send out mails from multiple IP addresses.

IndiMail has the ability to call a custom program instead of qmail-local(8) or qmail-remote(8). This is done by defining the environment variable QMAILLOCAL or QMAILREMOTE. qmail-remote(8) can use the environment variable OUTGOINGIP to set the IP address of the local interface when making outgoing connections. By writing a simple script and setting QMAILREMOTE environment variable pointing to this script, one can randomly chose an IP address from the control file

/var/indimail/control/outgoingip

The script below also allows you to define multiple outgoing IP addresses for a single host. e.g. you can create the control file to send out mails from multiple IPs only for the domain hotmail.com

/var/indimail/control/outgoingip.hotmail.com

Let us name the below script balance_outgoing

% su
# echo "/var/indimail/bin/balance_outgoing" > /service/qmail-send.25/variables/QMAILREMOTE
# svc -d /service/qmail-send.25
# svc -u /service/qmail-send.25
# exit
%

Finally the balance_outgoing script can be placed with execute bit in /var/indimail/bin

#!/bin/sh
# This scripts expects qmail-remote arguments on command line
# argv0          - qmail-remote
# argv1          - host   (host)
# argv2          - sender (sender)
# argv3          - qqeh   (qmail queue extra header)
# argv4          - size
# argv5 .. argvn - recipients
#
#
host=$1
sender=$2
qqeh=$3
size=$4
shift 4

cd /var/indimail
if [ " $CONTROLDIR" = " " ] ; then
    FN=/var/indimail/control/filterargs
else
    FN=$CONTROLDIR/filterargs
fi
if [ -n "$SPAMFILTER" -o -n "$FILTERARGS" -o -f $FN ] ; then
    # execute spawn-filter if you have filters defined for remote/local deliveries
    PROG="bin/spawn-filter"
else
    PROG="bin/qmail-remote"
fi
if [ " $CONTROLDIR" = " " ] ; then
    if [ -f /var/indimail/control/outgoingip.$host ] ; then
        IP=(`cat /var/indimail/control/outgoingip.$host`)
    elif [ -f /var/indimail/control/outgoingip ] ; then
        IP=(`cat /var/indimail/control/outgoingip`)
    else
        exec -a qmail-remote $PROG "$host" "$sender" "$qqeh" $size $*
    fi
else
    if [ -f $CONTROLDIR/outgoingip.$host ] ; then
        IP=(`cat $CONTROLDIR/outgoingip.$host`)
    elif [ -f $CONTROLDIR/outgoingip ] ; then
        IP=(`cat $CONTROLDIR/outgoingip`)
    else
        exec -a qmail-remote $PROG "$host" "$sender" "$qqeh" $size $*
    fi
fi
IP_COUNT=${#IP[*]}
if [ $IP_COUNT -gt 1 ] ; then
    i=`expr $RANDOM % $IP_COUNT`
    export OUTGOINGIP=${IP[$i]}
fi
exec -a qmail-remote $PROG "$host" "$sender" "$qqeh" $size $*

Post a Comment

Popular posts from this blog

IndiMail Installation for newbies in < 10 steps

Installing Indimail using YUM/APT Repository Install OS
OpenSUSE
openSUSE Leap 42.3
openSUSE Leap 42.2
openSUSE 13.2
openSUSE 13.1
SUSE Linux Enterprise 12 SP2
SUSE Linux Enterprise 12 SP1
SUSE Linux Enterprise 12
Red Hat
Feodra 27
Fedora 26
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 6
CentOS 7
CentOS 6
Debian
Debian 8.0
Debian 7.0
Ubuntu 17.04
Ubuntu 16.10
Ubuntu 16.04
Ubuntu 14.04
Ubuntu 12.04
Click the below URL for Install Instructions
https://software.opensuse.org/download.html?project=home%3Aindimail&package=indimail Shutdown MySQL if already running and disable MySQL from being started up by the system % /etc/init.d/mysqld stop % sudo chkconfig mysqld off % /bin/rm -f /service/mysql.3306/down
Start IndiMail
% sudo service indimail start Check Servicess
% sudo /usr/bin/svstat /service/* /service/clamd: up (pid 1014) 2985 seconds /service/dnscache: up (pid 1021) 2985 seconds /service/fetchmail: down 2985 seconds /service/freshclam: up (pid 1020) 2…

Using Docker Engine to Run IndiMail / IndiMail-MTA

IndiMail now has docker images. You can read about installing Dockerhere. Once you have installed docker-engine, you need to start it. Typically it would be
$ sudo service docker start
To avoid having to use sudo when you use the docker command, create a Unix group called docker and add users to it. When the docker daemon starts, it makes the ownership of the Unix socket read/writable by the docker group.
Warning: The docker group is equivalent to the root user; For details on how this impacts security in your system, see Docker Daemon Attack Surface for details.$ sudo groupadd docker $ sudo usermod -aG docker your_username
Log out and login again to ensure your user is running with the correct permissions. You can run the unix id command to confirm that you have the docker group privileges. e.g.
$ id -a uid=1000(mbhangui) gid=1000(mbhangui) groups=1000(mbhangui),10(wheel),545(docker) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
Now we need to pull the docker image for I…

Writing Filters for IndiMail

IndiMail provides multiple methods by which you can intercept an email in transit and modify the email headers or the email body. A filter is a simple program that expects the raw email on standard input and outputs the message text back on standard output. The program /bin/cat can be used as a filter which simply copies the standard input to standard output without modifying anything. Some methods can be used before the mail gets queued and some methods can be used before the execution of local / remote delivery.

It is not necessary for a filter to modify the email. You can have a filter just to extract the headers or body and use that information for some purpose. IndiMail also provides the following programs - 822addr(1), 822headerfilter(1), 822bodyfilter(1), 822field(1), 822fields(1), 822header(1), 822body(1), 822headerok(1), 822received(1), 822date(1), 822fields(1) to help in processing emails.

Let us say that we have written a script /usr/local/bin/myfilter. The myfilter program …