Mail not sent as an attachment

Hi,

I create a Service Process and then a Complaint for it by copying a material.

Next I click a Return Request, Subsequent Delivery and then Credit Memo. After this a mail will be sent to the Email address of Sold to Party.

The Email is generated using a Smartform. The output of Smartform should arrive as a PDF attachment in mail but it is not coming as an attachment.

It is coming as a simple mail. is there any setting to be made for this.

Thanks,

Prasanna