Each message has one or more recipients. Recipients can be Redbex system users and user groups.

If the recipients of a message includes user groups the members of this user group are evaluated to users when the message is sent. The message is then associated with each member of the user group. I.e. if the members of a user group change later on this will not influence the recipients of already sent messages. It is also not possible to reconstruct the recipient groups for delivered messages.

When a message is addressed to a user more than once, either through double user recipients or through evaluation of user group, recipients it will still only be associated (delivered) to this user only once.

Recipients can be acknowledging recipients or non-acknowledging recipients. Acknowledging recipients will be asked to acknowledge the receipt of a message, non acknowledging recipients cannot acknowledge the receipt of a message.