Is it possible to have an email account on exchange server 5.5 to be forwarded to an sbcglobal.net account automaticlly.

Yep. Its been a while since I'vebeen in the 5.5 interface. Define a custom recipient with the sbc email address. In properties of the mailbox..... find the delivery options and set it to send it to the custom recep.. you defined. I admit it is a loose description. Its been probabily 3 years since I touched a 5.5 box.

Create a Custom Recipient with the address that you want to send the mail. On the mailbox set this CR as Forward mail to... I dont have Exchange 5.5 admin in front of me so I am little uncertain about the Forward mail to... is the correct term. if you want you can hide the CR from GAL afterwards.