If you receive your messages from an IMAP server, you can work in offline mode. You can work in offline mode to reduce the amount of time that you spend online.
When you switch to offline mode,
Email and Calendar
creates a local copy of folders that you have selected for offline use. You
can read and respond to the messages in the folders in offline mode. When
you send a message,
Email and Calendar stores the
message in your Outbox folder until you switch to online
Offline mode is not the same as being disconnected.
Email and Calendar completes all actions
that you performed offline when you return to online mode.
To specify which folders to create copies of when you are in offline mode, see Setting Folders Preferences.
To switch to offline mode, choose File -> Work Offline. Alternatively,
click on the connected cables icon at the bottom left of the
Email and Calendar window. A cross appears through the connected
To switch to online mode, choose File -> Work Online. Alternatively, click on the connected cables icon. The cross disappears from the connected cables icon.