The offline message system is FUN. There was one time I tried to log in but had a crash and missed a few offline messages. Messaging through HG is problematic too. I want people to message me easily when they visit my world so I created this little GEM. I am not trying to re-create the wheel here, just performing a task differently. 

Usage: Add this script to any object, it can have your picture if you want. When touched, the user will get a dialog with which to send you a message. When the sibmit button is pressed the message is written to a notecard inside the prim and the owner is notified on next login that messages are waiting in the mailbox prim.  

Thanks Ubinu for the idea... I nicked some of Satyr's old code snippets to compile this HOT MESS for xengine. Enjoy!