A label of a message to be sent is detected as a message label for a non-real-time transmission. For a user device group associated with the message to be sent and based on a timely-response rate and a correction scheme, an optimal time period to respond to a message for each user device in the user device group is dynamically determined. Based on the optimal time period for each user device to respond to a message, the message to be sent is separately sent to a corresponding user device in the user device group.