The coronavirus situation has made an own, DESY-wide messaging (chat) service more important. Therefore, the Mattermost software is now (15.4.2020) available for this purpose. The introduction is initially temporary according to the decision of the DESY board of directors. Should a permanent need be identified, a permanent offer is also imaginable. A decision on this will be made at a later date.

If you have questions or suggestions, please contact the UCO (, Tel.: 5005).


The focus in April 2020 was on the fast availability of a text chat service at DESY. Apart from stabilizing the service in DESY-wide user operation, various extensions of the service are imaginable for the future, such as the addition of audio and video (with a limited number of participants). The procedure in terms of content and timing still has to be coordinated.



We use Mattermost in the E10 Plan version for cost reasons. This is accompanied by certain restrictions such as the impossibility of synchronizing DESY Registry groups with Mattermost. In addition, the number of participants is limited to 3,000, so that there may be usage restrictions when the number of licenses is reached.

Please read the general information. (See below).

General notes
  • The messaging service is based on servers in the DESY computer centre.
  • The use of the messaging service is voluntary.
  • The messaging service is not a substitute for e-mail - it complements e-mail: E-mail is the comparatively more formal exchange comparable to the classic letter, while messaging/chatting is more like the less formal, casual exchange between door to door or in a meeting or coffee round.
  • In particular, the messaging service does not serve as a permanent storage medium, not as a documentation medium and also not as an official message medium for communication - for these purposes there are file systems or Sync & Share, websites or Confluence and e-mail.
  • Accordingly, data from chats is neither archived nor is it possible to recover individual deleted posts.
  • At present (8.4.2020) chat histories are still stored for an unlimited period of time and can therefore be viewed by chat members - there is a high probability that this will be limited in time in future.
  • Confidential data, especially personal data, should not be exchanged via the messaging service.
  • After 60 minutes of no input in the messaging service, the status of the user is automatically changed from "Online" to "Absent". This does not mean that there is no input on the computer.
  • It is possible to set the status to "Do not disturb", so that no notifications about incoming messages are not sent.


The initially existing "DESY" team comprises all account holders existing at DESY. This ensures, among other things, that cross-group channels can be set up for projects, for example.

The establishment of teams should be supported by DESY group leaders or DESY departmental representatives and correspond to the DESY registry namespaces. Accordingly, teams can only be set up by the system administrators. If necessary, please contact the UCO (, Tel. 5005).

There are no restrictions on setting up channels in the teams.







In Mattermost a distinction is made between "Team" and "Channel". For both, there is no limit on how many can be joined.

  • Team: A team includes a larger number of people and any number of channels. A team cannot have "sub-teams". In each team there are the two automatically created channels "Town Square" and "Off Topic".
  • Channel: A channel is a virtual room where added people can write with each other. A channel is always assigned to a team. To join a channel (public) or be invited to a channel (private), the user must be part of the parent team.
  • Town Square: The Town Square is an automatically created channel that exists in every team and contains the entire team. It is reserved for official topics.
  • Off Topic: The "Off Topic" channel is the second automatically created channel, which also contains the entire team and is intended for further team communication.
  • Private VS Public: Teams and channels can be either "Private" or "Public". Anyone can join a team that is public. In a private team, you must either be invited via a shared link or added by a team administrator. The same applies to a channel, except that you can only join a public channel if you are part of the parent team.


Further links

Installation guides