Mail syncing problem
One Folder in apple mail not syncing with other devices .
All other folders syncing on other devices.
Mail being dragged and dropped from all mail to the folder
iMac 27″, macOS 10.13
Question marked as
Go under Window menu -> Activity. It will usually indicate what process is stuck. You may have the wrong login settings or server settings. Preset server settings for AOL, Yahoo, Verizon, Gmail/Google may no longer work on older operating systems, and using the Other... server setting on the IMAP settings for the account usually works better.