I tried to resend the same email message to the same Target Audience but the system filtered everyone out. By changing the message contents, can I resend the email to the same group of constituents?
No, changing the contents of the email will not allow re-delivery to the same constituents. Luminate Online looks to the Message ID to prevent constituents from receiving the same message. In order to send a message that has previously been sent to the same Target Audience, you will need to copy the message. In this way, you are generating a new Message ID and allowing the system to send a new message (even if the contents are the same).