I think I've found a solution to the problem some of us are having. http://jira.phoenixviewer.com/browse/PHOE-3663 https://jira.secondlife.com/browse/SVC-7540 It appears this is a sever issue that only effects some accounts, particularly those that have an empty mute list. It worked for me, as soon as i hit mute an entire weeks worth of offline messages came flooding in.
I'm having the same issue as nana. I thought it was related to the newest phoenix update(1600), but i can't see how it would stop offline deliveries. I can still recieve offline objects from friends, so maybe it's limited to objects delivering things?