Updated : Jul 20, 2015 in Linux

Relay emails for specific destinations

In the last couple of years many large email providers have started to refuse emails coming from certain IP addresses or according to certain other…

Updated : May 19, 2015 in Linux

Installing DMARC filtering in Debian Wheezy

Principle: DMARC is a bit of a strange animal. It serves as a filter against SPAM but only according to the rules given by the…

Updated : May 07, 2015 in Linux

Anti-SPAM mail filtering using SPF on Debian Wheezy

Install the package: apt-get install postfix-policyd-spf-perl Add this line to /etc/postfix/main.cf: policy-spf_time_limit = 3600s Add the following lines to /etc/postfix/master.cf: policy-spf unix - n n…

Updated : May 07, 2015 in Linux

TCP Load balancing email/web servers with NginX

I've got 2 synchronized email servers running and, in order to make sure I don't have to change the servername settings of my mail client…

Updated : Mar 19, 2014 in Linux

Archiving all incoming/outgoing mails using Sieve

The following custom Sieve script can be used to make a copy of every email a user sends or receives. In the example, the user…

Updated : Mar 19, 2014 in Linux

Blocking user to send sensitive information using Sieve

The following article uses examples to show how to block users from sending attachments containing sensitive information (e.g. financial information) to the outside world. The…

Updated : Mar 19, 2014 in Linux

Force sending mails using SSL/TLS

Introduction: In some cases it might be requested to transfer emails to another mail server using encryption (SSL/TLS). Here is a way to do it…

Updated : Jan 20, 2014 in Apache

Creating a XEN machine and Installing Group Office in Debian Wheezy

Introduction In this Tutorial I will explain the steps I did to create a Xen Virtual Machine with minimal packages and then install the latest…

Updated : Apr 01, 2013 in Linux

Install Geotrust/RapidSSL certificate in Zimbra 8.0.x

This How-to is based on the following page and after failing to install myself my commercial certificate I feel very grateful for his contribution: http://elijahpaul.co.uk/2012/12/installing-a-rapidssl-certificate-on-zimbra-8-0/#.UVjDBhlSP5g…

Updated : Mar 15, 2013 in Linux

Installing OpenDKIM in Debian Squeeze/Wheezy

Introduction Lately my mail server started to get refusals of emails from large mailing systems like AOL, Yahoo etc. I can't blame them for trying…