Have wasted about a week with this problem. Write a reply and it sits in Outbox and no amount of clicking on Send/Receive will make it go. No wheels turning, nothing. I open desktop in the morning and no new emails come in for hours until I quit and restart the program. It even happens on my work computer. Tech support keeps asking for a zdesktop.log which I cannot find and he hasn't given me any usable instructions on where or how to find it. This is taking up way too much time. I also get warnings that yahoo is blocking the synching of emails so I have to go to yahoo site to read them so I might as well just forget zimbra and use yahoo and gmail websites...much more reliable.