Attachment of PDF document to external Mail id - error

Hi All,

I am converting a smartform into pdf and then attaching it for sending to external mail id.

All this work fine and mail with attachment is sent successfully.

When i try to open the attachement i get the error msg "There was error opening this document. The file is damaged or could not be repaired."

I am excuting this through FM SO_NEW_DOCUMENT_ATT_SEND_API1 and running this in CRM 7.0 system.

When we send text file there is no problem with the same function module but the prob is only with PDF formats.

Can you please help me as in to check if some special setting required for PDF mail sending or what else to check in the system to rectify this error.

Thanks.