Author Archive for Christian Mollekopf

Action required for Group managers!: Change to DKIM-Signatures – domain alignment – Errata

Posted on: December 24th, 2024 by

Due to the perils of simultaneous wordpress editing a crucial error snuck into the previous blogpost:

The newly required DNS entries are:


dkim1._domainkey CNAME dkim1._domainkey.kolabnow.com.
dkim2._domainkey CNAME dkim2._domainkey.kolabnow.com.

and NOT as the previous blogpost claimed


dkim1 CNAME dkim1.kolabnow.com.
dkim2 CNAME dkim2.kolabnow.com.

The previous blogpost has been corrected meanwhile.

Apologies, and merry Christmas!

Incident: Service outage

Posted on: November 6th, 2024 by

Kolabnow is currently experiencing a networking infrastructure interruption. We apologize for the inconvenience while we investigate the issue.
We will update this blogpost as soon as more information is available.

2024-11-06 @ 05:44 UTC: This issue was triggered by one of our hypervisors spontaneously rebooting. Most services have been restored, the Operations team is working through remaining issues. Users can login and use the facilities.
2024-11-06 @ 07:17 UTC: The incident has been resolved.

Bleib sicher Zuhause mit Kolab Now

Posted on: March 22nd, 2020 by

Kolab Now unterstützt alle, die auf Homeoffice nicht vorbereitet sind, indem wir unseren Service für die Dauer der Krise gratis zur Verfügung stellen.

Email, Kalender, Office-Dokumente und mehr, helfen Ihnen Ihre Arbeitsabläufe auch Zuhause aufrecht zu erhalten.

Registriere dich jetzt mit dem Voucher Code KOLABFROMHOMENOW.

Dieses Angebot werden wir so lange wie möglich aufrechterhalten und nachdem sich die Lage beruhigt hat wieder entfernen.

Kube Campaign: Last Chance

Posted on: August 29th, 2018 by

The proposition of the Kube campaign is the following:

You sign-up now via Kube for a Kolab Now account, and pay only for the currently available feature-set that Kube provides at the moment. The web client will be limited to the same feature-set, but as Kube progresses and covers more features you will also get those features for the web client, while you get to keep your reduced subscription price.

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Quick keyboard navigation in Kube

Posted on: August 13th, 2018 by

It was already previously possible to navigate through Kube by moving the keyboard focus using tab and arrow keys, however that is neither fast nor efficient. To be able to really blaze through your Inbox we naturally require VIM style keybindings. To move through the UI we want to be able to go through folders, threads and mails using a single key press, without worrying where the focus currently is.

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A short guide to LMDB

Posted on: June 7th, 2018 by

LMDB is a great embeddable key-value store that we use extensively for Kube.

Using it is not completely straightforward though, so here’s a short guide for future reference.

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Kube on Mac OS

Posted on: April 3rd, 2018 by

Kube on Mac OS

After a week of getting to grips with how Qt development on mac works and wrangling various build issues, I am pleased to finally report success =)
Kube on Mac OS is alive!

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Kube’s gained some manpower

Posted on: March 29th, 2018 by

Around FOSDEM this year we have found some fresh manpower for Kube! Please welcome Rémi, who is doing an internship with us, and is working on Kube during that time. He was quick to land his first few patches and is now busy implementing the first few steps for CalDAV based calendaring support.

I for one am exited to see what he will come up with =)

Find your mails with fulltext search

Posted on: February 26th, 2018 by

The most recent addition to Kube is fulltext search. It’s a complex enough topic that we don’t really want to implement it in our key-value store that we use for the rest of the data, which is why we’re using Xapian to do the heavy lifting.

Kube is an offline capable client, and as such we also want search to work without an internet connection. However, we naturally can only search the data that you have available locally. Normally this means we’ll have subject and recipients indexed for all your mail, and the complete content for all mails that you have every viewed/downloaded.

In the long run we’ll want to extend that with server-side searching for when you’re connected to the server, so that you could indeed search through all your data, without having to first download it all. But that is a task for another day.

So here it goes; Fast as you type searching of your emails:

Searching a folder with 50k messages.

For more info about Kube, please head over to About Kube.

Using and abusing memory with LMDB in Kube

Posted on: February 13th, 2018 by

When synchronizing a larger folder in Kube, you’ll notice that the memory usage is growing at an alarming rate.

Surely something must be wrong? Let’s dig into that.

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