SideNotesIM - Send Offline Messages
You can send an Offline Message to a user that is greyed out in your active users list by either double clicking on the user or right clicking on the users name and selecting 'Send Offline Message'.
When a user sends an offline message it is placed in an outbound message queue that is separate from your main message log. Because SideNotesIM does not use a central server this message is stored locally and will not be delivered until both the sender and recipient are online at the same time. You can view your offline message queue by clicking on the down arrow to the right of the History button and selecting View Sent Offline Queue. Deleting your message history will not delete any messages in this outbound queue.