COS (Class of Services)

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Category of Services (COS)

A COS establishes defaults for a variety of settings and decides which things and how they may be accessed by a web client. From the Settings page on the web client, a user who is a member of that COS can subsequently modify some of these settings.

Click the CREATE NEW COS button and give your COS a name. The choices may then be configured using the menu on the left.

Features Features are options that control whether a user may use Carbonio’s most popular features through a web browser or a mobile app. Some of them may be activated or disabled using the CLI; for details, see the section Setting Features through the CLI.


For each component (Mails, Calendar, and Contacts), preferences include standard choices.

The first is the language that COS members will automatically use, which also includes the location. The remaining choices relate to

  • Carbonio’s standard look in web clients: whether emails are shown as dialogues, for instance, or if the calendar displays a month or a work week.
  • the default settings or behaviour of the features, such as how frequently to check for new emails or whether new email contacts are immediately added to Contacts.
  • which functionalities the user may access: whether a user is permitted to forward emails or whether they may establish a filter to only forward certain emails, for instance.
  • Sending the read receipt to the email sender by default: always sending it, never sending it, or asking each time

Server Groups

On this page, you can choose which servers new COS users can be added to.


The Advanced Option lets you customise things like user quotas, passwords, and rules.

A user’s space on the server or the number of contacts he can have are both restricted by the user quota, which is a set of settings. It has the choice to send recurring alerts when the user space rises over a predetermined level.

The user passwords’ length, character count, and duration may be customised using the password settings. Additionally, you can reject often used passwords.

The behaviour of Carbonio when a user fails to log in may be defined using the Failed Login Policy. When three consecutive login attempts fail within 30 minutes, a normal policy can lock out the user for an hour.

The token’s validity period is covered by the timeout policy.

How long emails will be kept before being automatically erased is outlined in the email retention policy.

Finally, when utilising an Exchange server, the Free/Busy Interop option enables the provision of O and OU records to display the free/busy user schedule.