A method can include receiving a request for a read receipt by a first user of a predetermined user group for a session. The request for a read receipt can refer to an information segment of the thread supplied with a tag by the first user. The tag can include a predetermined character string identifying at least one second user from whom the first user requests the read receipt for the tagged information segment. The second user can be identified in a database, a notification containing the information segment to at least one second user can be sent and an acknowledgment message from the second user that he has read the notification containing the information segment can then be received for assigning a read receipt to the information segment as soon as the at least one second user has read the notification.