Adding Signature in Entourage Launch Entourage. Click on Tools menu and go to Signature . On this window click on New & enter the signature of your choice and give a name to your sign. Once done, click on close button on top left and it will prompt you to save the sign that you have created. Setting a default Signature in Entourage Launch Entourage. Open Entourage menu and go to Account Settings . On this new window go to Options tab. Under Default Signature select the name of the sign that you want to be set as default and click on OK. Changing a Signature temporarily This can be done from the New mail window itself from where you compose a new mail. Click on the pen icon that denotes signature and it will open a drop down displaying all the signs that you might have created. Select the appropriate on and continue composing your mail. It will have the new sign.