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Author: halfgaar

Halfgaar is Wiebe. Wiebe is a contributing author on this weblog. He also has a lot of stuff (such as long, in-depth articles) on his personal website.

Wiebe works at YTEC, where he is a senior developer of customer-specific tailor-made software (“klantspecifieke maatwerk software“) for clients in a few select markets: wholesale, printing and healthcare.

Debian volatile: keep fast moving packages working on Debian stable

The concept of Debian stable is kind of nice, since you don't have to be affraid of upgrade breakages all the time, but it can also be annoying, because things like spamfilters and virusscanners are fast-moving and you often end up with old versions of those. That is why the Debian volatile project exists. Read More »

Configuring VPN server and client on Linux

Basically, there are two types of VPN's: IP route and ethernet bridge. I configured an IP route VPN, based on this document. Read More »

Adding Microsoft docx and similar to Mailscanner whitelist

in /etc/MailScanner/filename.rules.conf: allow \.docx$ - - allow \.xlsx$ - - allow \.x(ml)?\d{0,}\.rel$ - - Read More »

666 posts on tweakers

I wanted to mark this notable event: Read More »

Configuring Nagios to check a HTTP host

Nagios is an elaborate piece of software to monitor hosts and services. I will explain a bit how you can configure nagios to monitor an HTTP service. I'm assuming your nagios setup already has the default config files generic-host_nagios2.cfg and generic-service_nagios2.cfg, which tell nagios how to monitor hosts and services. Read More »

Disable Zimbra’s duplicate mail detection

Zimbra can discard duplicates of incoming mail. This has certain advantages, but for us, where different people use the same account with different identities, this prevents a message from being delivered to multiple virtual inboxes. Read More »

Lowering Bayes score for Zimbra’s Spamassassin config

The Spamassassin config in Zimbra has a very high default score for bayes matching of 99, 95, 90, etc, percent. A mail with subject and body "test" or "asdfaewf a" is often marked as 99% bayes, even though the spamfilter has seen no training mail. This is absurd. Read More »

Configuring fetchmail to deliver to Zimbra with custom header added

I needed to fetch mail from a POP3 account and deliver it to a Zimbra account. Because I'm doing this for multiple POP3 accounts, I want to add a header which I can use in Zimbra to filter. This is what we made: Read More »

Fixing spamassassin rule in Zimbra

Spamassassin has had a bug for a while, marking any mail from 2010 and later as spam because it's from "far into the future". This was very crudely done as this regexp: /20[1-9][0-9]/. Because of that, almost all mail from 2010 onward is marked as spam. Read More »

Scanning the entire network for machines with nmap

You can easily scan the entire network for machine presence with nmap: nmap -sP -v -v 192.168.1.* Read More »