New to em client. I repeatedly have an issue that when I move a file from the inbox (or any other folder) to a folder in another account, that folder upload hangs on a synch at 99%. Only fix is to delete the account and set up again. If I copy the same message back to the inbox both the inbox and the original folder hangs.
Moving between accounts is quite complicated, especially if the message attachments are quite large. The contents first need to be downloaded locally then uploaded to the other provider, then if you have configured for offline use, it needs to be downloaded again. So lots of opportunity to take a while.
Are you getting any errors? You can look in Menu > Tools > Operation > Log.
You could also uninstall eM Client and then download and install 7.2.35595 from the Release History. See if there is any difference.