Author Archive for Mads Petersen

The Annual Certificate Refresh

Posted on: January 2nd, 2023 by

Another year past and we needed to again refresh our certificates.

As in previous years, e.g. 2018, 2019, 2020, etc, we rolled over certificates across all systems over the last few days of the year.

The new certificate is in place, and applies to, imaps:// and smtps://

As in previous years, we publish the fingerprint here:






Incident report: db server stuck in large operation..

Posted on: June 7th, 2022 by

On Monday June 06 2022, from approximately 11:24 UTC a group of Kolab Now users observed an error stating: “Gateway time-out” when trying to login to the webclient, the dashboard, or connect with any desktop or mobile client. The Kolab Now main page and all other services (Support, blog and knowledge base) were available with no issues for these same users.

The issue lasted for about an hour, until approximately 12:19 UTC, and was caused by a db server in one of the clusters being stuck in a large operation. The issue caused troubles with the login procedure, but had no impact on the mail flow. No mail was lost or delayed during the incident.

The operations team was warned by the monitoring system about a stuck db server in the cluster, and was having hands on keyboards right away. The issue lasted for about an hour (some users in the group saw return of service earlier than others), and was caused by this db server in the cluster being stuck in a large operation.

Further investigation and action is going into reevaluating the amount of resources assigned to the db clusters and other servers for such large operations of this type.

If you were among the group of users that was impacted by this, then please accept our apologies for any inconvenience caused.

Updates to Kolab Now..

Posted on: April 22nd, 2022 by

This Friday the operations team is rolling over the Kolab Now system and deploying a set of new updates. However, thanks to the redundancy in the architecture, users will not see any downtime or service interruptions.

The update contains a lot of code, preparing the system for future features, and one update to the Voice & Video feature.

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Is your password ‘123456’?

Posted on: February 14th, 2022 by

If so, you share your password with thousand – perhaps 100s of thousands of others. Password complexity is being talked a lot about in the media these days. You have probably seen messages from your bank or your badminton club membership administrator about how your password should be complex to avoid password cracking.

Last Friday, 2022-02-11, Kolab Now released a number of enhancements, most of which are not directly visible to end users. However one change that could have impact for users is the option to implement password policies.

Take a look at the knowledge base article, to see how password policies can be leveraged by group owners to ensure all users have adequate passwords at all times.

This release also brings some interesting updates for the users in the Private beta program, who now have access to Shared folders, Distribution lists, and Resource management – more information to follow on that.

More interesting updates are on the way. Keep an eye on this blog for news and updates.



Our Statistics for 2021

Posted on: February 4th, 2022 by

Again this year we deliver you the numbers according to our terms of service, that states there’s basically no way for anyone to get any access to your data without us letting the world know that it happened.

We have again counted the interactions and here is our statistics for 2021.

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Incident report: Failing front ends

Posted on: January 26th, 2022 by

On Friday January 21 at 15:48 UTC  users observed that the main page became unaccessible and reviled an error: 503 – Server unavailable. The webclient ( was still available, but with seriously degraded performance – to the point where the service would give up and reveal the ‘Maintenance’ page.

Also IMAP, SMTP, ActiveSync, and $DAV was impacted by the failing frontends.

The service was unavailable for about 50 minutes, during which time all mails, in and out, were queued. When the service again was available, those mail queues first had to be delivered before new mail could be sent or received. This caused users to experience a delay in the traffic.

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Incident Report: WebDAV/CalDAV/CardDAV services unavailable..

Posted on: January 17th, 2022 by

On Monday morning at 03:22 CET the kolab Now $DAV services stopped working.

While resolving a performance issue for $DAV connections, we moved around  servers from an old infrastructure to a new infrastructure, and with that the rotation of logs. Unfortunately a tiny bit were missed while configuring the new servers, which caused the log rotation attempting to reload httpd (while that wasn’t needed). In turn, reloading httpd didn’t succeed and timed out, and the new DAV servers were left in a maintenance state;  unavailable.

This happened at ~ 03:22 CET. As these are new DAV servers, they were only included in the standard monitoring, and no one got notified about the problem until it was discovered at 07:47 CET. The configuration was promptly corrected and the new DAV servers came back online right away (and was added to the monitoring notifications). At this time everything should be available and working as expected.

We apologize for any inconvenience that this may have caused.

The Annual Certificate Refresh

Posted on: December 28th, 2021 by

Another year past and we needed to again refresh our certificates.

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Incident Report: Network Outage at Kolab Now

Posted on: October 5th, 2021 by

On Tuesday 2021-10-05, between 10:20 UTC and 10:40 UTC, a network issue kicked our firewalls off the grid, and Kolab Now was down. Our Operations team was on the case right away and could correct the issue instantly. As a result the downtime was very limited.

When the dust had settled, it turned out that one of our hypervisors had stopped one of its redundant storage blocks, as it was unavailable for too long, and a group ~ 20 users were unable to see their mails in the mail folders. Again our Operations team was reacting fast and could restore the connections to the redundant storage. Everything is back up and running for everyone now, and no data was in danger at any point through out the incident.

If you are one of the few users who had the problem after the down time, or if you experienced troubles during the outage around lunch time, then we truly apologize for the inconvenience that it caused.

If you have any questions or concerns in this context, please contact support.

(re-)Introducing Bank payments..

Posted on: August 10th, 2021 by

On Saturday, 31st of July 2021 we added a few features to Kolab Now during a service window. We already informed you about two of the features that were added; the user controlled Sender Preferred Framework (SPF) for group admin users, and the user controlled opt out of the greylist for users. What we failed to update you on was another added ‘new’ payment option: Bank transfers.

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