While offline, no new messages will be downloaded or interrupt you; manually clicking "Send/Receive All Folders", however, (or pressing F9), will force Outlook to check for new emails / send those in your outbox. But it will remain offline after that. Tip: Outlook 2010 can automatically send receive even when offline, but with a different interval than the default one. See "Send/Receive Settings" to customize this behavior. ![Send/Receive settings when Microsoft Outlook is offline](/i/Send-Receive-settings-when-Microsoft-Outlook-is-offline.png)