Make Outlook the default program for E-mail, Contacts, and Calendar
If you install multiple e-mail programs on the same computer, you can ensure that Microsoft Outlook is used when you send e-mail messages from any non-mail program.
For example, one of the following scenarios can occur if Office Outlook is not your default e-mail program:
If you try to send a spreadsheet to a mail recipient from Microsoft Office Excel that is on a computer that has Office Outlook and Outlook Express installed, Office Outlook might not be used to send the e-mail message.
If you click a link on a Web page that is intended to open a new message window, your computer might not open the Outlook new e-mail message window, or it might use a mail program other than Outlook.
When you send a file from a program by pointing to Send To on the File menu, and then clicking Mail Recipient, the e-mail program that is set as your default mail client is used to send the file.
The following steps will set Outlook as your default mail program.
On the Tools menu in Office Outlook, click Options, and then click the Other tab.
Under General, select the Make Outlook the default program for E-mail, Contacts, and Calendar check box.