Working Offline
Evolution can keep a local copy of folders located on remote mail systems like IMAP or Exchange, to allow you to read messages.
Evolution's forced offline mode only refers to mail and does not apply to contacts and calendars.
POP mail downloads all messages to your local system, but for remote accounts usually just the headers are downloaded. The rest, such as the body of a message, is downloaded only when you want to read the message. Before you force Evolution to be offline, Evolution downloads the unread messages from the folders you have chosen to store.
Account settings
The Receiving Options of remote accounts offer an option to Synchronize remote mail locally in all folders which is applied to all folders of that account.
To avoid downloading large amounts of data, you can also disable synchronizing messages which are older than a certain time period.
Marking folders for offline usage
If you do not have Synchronize remote mail locally in all folders for the account enabled, you can synchronize individual folders.
To mark a mail folder for offline use,
Right-click the folder, then click Properties.
Click Copy folder content locally for offline operation.
Syncing messages for offline usage
Your connection status is shown by an icon in the status bar of the main window. When you are online, it displays two connected cables. When you force offline mode via clicking the icon or via File ▸ Work Offline, the cables separate. You can either go offline immediately or synchronize remote folders with your local copy before you go offline.
To synchronize folders without going offline immediately, select File ▸ Download Messages for Offline Usage.
Automatic Network State Handling
Evolution automatically understands the network state and acts accordingly. For instance, Evolution switches to offline mode when the network goes down and automatically switches on when the network is up again.