can’t email from Simply Accounting

Hi, I used to be able to email my purchase orders from Simply Accounting but now I can’t. I am using Windows XP and have Microsoft Office Basic 2003 installed but our company uses Outlook Express for email. I have made sure that Outlook Express is selected in Internet Explorer options but for some reason the purchase orders go to my outbox in Outlook. Because it isn’t set up I can’t send from there. I do get a message that a program is trying to access my address book in Outlook and I select Yes to continue and then get another message that a program is trying to automatically send an email on my behalf and select yes to continue. When I check my sent box in express there is nothing there.
Thanks for your help