Mail Manager supports the filing and searching of messages in locally sync'd Dropbox folders.
The process is the same as local and network folders.
e.g. C:\Users\<user_name>\Dropbox\Projects\119000\119363 - Tower Hill\0.00 Email
Note: If you intend sharing the filing locations and filed emails it is important that the path to the folders are the same for all users.
When setting up the users root Dropbox folder, avoid using the default "C:\Users\..." folder i.e. use the local root folder e.g. C:\Dropbox\... That way the filing locations will be common to all users.
How to move my Dropbox folder to a new location
A local Dropbox folder can also be used for the Shared Configuration Folder e.g. C:\Dropbox\28Hands\Mail Manager Config