@jakob I've come up with an ingenious way to save your server's drives from overflowing:
gs -sDEVICE=pdfwrite -dBATCH -dNOPAUSE -dQUIET -sOutputFile=out.pdf in.pdf
With this you can remove all attachments except text and images. I've confirmed that the remaining size is mostly images by running `pdfimages -all in.pdf /tmp/out`. I think I'll make me an `unbloatpdf` alias or something.