How can I manage and maintain a folder of inbox mail ? It will increase a size of folder after I use one year or so. The outlook of Office product has a way to maintain a file folder such as pst.file. You can divide them depending on a year for example and save them in other HDDs.
eM Client can manage the Inbox size on the server by using Automatic Archiving. This will remove messages from the server that are over a set age, and store them in a local folder in eM Client. This reduces server usage and organizes older messages into a separate folder.
The archive folder will also be a separate directory in your database, so that also reduces the size of the current Inbox/Sent etc. database files.
You can set this up in Menu > Tools > Settings > Mail > Automatic Archiving.