Open the Tools menu and choose Options.
The Options dialog box opens. Click the Mail Setup tab.
To send messages manually rather than automatically when you are connected to the Internet, uncheck the Send Immediately When Connected check box.
Click the Send/Receive button. The Send/Receive Groups dialog box opens.
If you click the Send button while connected to the Internet, Outlook immediately sends the message you created. You can, however, change Outlook's settings so that messages are sent manually. You make this change and adjust other related settings in the Mail Setup tab of Outlook's Options dialog box.
To change how often Outlook checks for mail while you are online, mark the Schedule an Automatic Send/Receive Every check box in the When Outlook Is Online area and type a time (in minutes) into the spin box.
To set offline connection intervals in the When Outlook Is Offline section, mark the Schedule an Automatic Send/Receive Every check box type a time (in minutes) into the spin box.
To control how Outlook connects to your mail provider, choose the desired options in the Dial-up area of the Options dialog box. When you're finished, click OK.