Tag Archives: Mail Server

Software, TechBlog

How to eliminate spam and protect your name with DMARC

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 If you are reading this you are probably making my life harder

E-Mail sucks! Your users just keep clicking the links in those damn phishing mails. And you can’t do anything about it. Hell somebody might be sending spam in your name and you have no idea about it. Let me blow your mind: You can solve these problems, for free. And I will introduce you the tools you need.

The cure to your E-Mail headaches hides behind three small acronyms:

  • SPF: Sender Policy framework, tells others which mail servers are authorized to send E-Mail for your domain.
  • DKIM: Domain Keys Identified Mail, uses encryption and DNS to verify an E-Mail sender and that it was not altered in transit
  • DMARC: Domain based Message Authentication, Reporting and Conformance. Builds on SPF and DKIM and implements a policy and reporting system around them

Continue reading How to eliminate spam and protect your name with DMARC →

Software, TechBlog

Debian Wheezy E-Mail Relay for multiple Domains and IMAP Server with Postfix Dovecot and Fetchmail

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One of our customers needed a way to use multiple mail domains. He already had a SBS2011, The Exchange Server on it was configured for the primary E-Mail Domain of the Company. The E-Mails from this Domain were fetched with the POP3 connector and all outgoing Mail was sent to the smart host of the E-Mail Provider.
The additional E-Mail Domains required a similar setup.
Unfortunately Exchange does not allow you to change the smart host for outgoing E-Mail based on the sender. There are third party Exchange addons, that do provide this ability, but I preferred to solve the problem with a Linux Mail Server. The configuration I will describe to you is fairly basic and the scenario it is used in is somewhat special. But the Article will still give you a fairly good impression on how to get a basic Mail Server running and how all the different pieces work together.

Continue reading Debian Wheezy E-Mail Relay for multiple Domains and IMAP Server with Postfix Dovecot and Fetchmail →

Software, TechBlog

Installing Horde 5 and configuring it for Active Directory and Dovecot

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I have been using Horde for quite some time as my Webmail solution. Unfortunately the Update from Horde 4 to Horde 5 always produced some issues on my system, so I decided to do a fresh install. My old Horde was a very simple Setup: It used the IMAP authentication of IMP  to authenticate users against my Active Directory. While this certainly works, this time around I want to configure Horde to authenticate against my Active Directory directly. Additionally I wanted my to use my Active Directory as Global Address Book for Horde.

Continue reading Installing Horde 5 and configuring it for Active Directory and Dovecot →

Software, TechBlog

Migrating Postfix and Dovecot from a MySQL User-Database to Active Directory

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When I set up my Active Directory, I wanted to migrate all services at home to authenticate against it. Now that I had the AD running and a few not so critical services used it, it was time finally migrate this one. I don’t have an Exchange-Server at home(nor do I want one) and my colleague who tested Openchange said it is not quite ready yet. So I will have to do without Exchange-extensions for the AD. I will still be able to do the basic management for my mail users in the AD, but I won’t be able to use any of the exchange extensions or tools for it. Continue reading Migrating Postfix and Dovecot from a MySQL User-Database to Active Directory →