PO PDF Size Reduction

We are attaching PO printout from Smartform converted to PDF , in a mail to the Vendor. There is nothing unusually large in this PO. Just normal Logo  which is of small size, and existing fonts. But the PDF size is around 0.5 MB. USer expects a smaller size attachment. Is this possible?

I am converting Smartform output to Pdf using otf data.

Regards,

Liji