Leopard's Mail now has a feature that lets you choose any one of your configured outgoing mail servers as you compose each message, which is particularly handy for laptops that connect to different Internet service providers.
To enable this handy feature, in Mail choose File » New Message. In the New Message composer, just below and to the left of the Subject: field, there's a customize button that displays a drop-down menu. Click the button, then choose Customize from the drop-down. You can then choose any or all of several optional controls that will be displayed on all New Message windows. In addition to displaying the Cc: and Bcc: and Reply-to: fields, you can now choose to show a drop-down listing the available outgoing mail servers, and another lets you set the message priority.
Mac OS X Hints
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