If it is at all possible, your email from your SAS session should be sent using SMTP.
When you use a client as an interface, such as MAPI (which is Outlook and other M$ apps) or VIM (which includes Lotus Notes, ccMail and others) then the client will intervene and you'll get errors such as this. You may also find that the address can be changed by the email client.
These and other issues have been addressed in a number of papers including the one at
http://www2.sas.com/proceedings/sugi31/256-31.pdf.
Kind regards
David