Make mobis downloaded via a recipe smaller

[sup]

My e-mail provider refuses to send my downloaded news to my Kindle because the files are to large. I came up with this code (do not run if you have a tmp directory in your working directory):

ebook-convert big.mobi tmp.epub
unzip -d tmp tmp.epub   
cd tmp
find . -type f  \
-iregex  '^.*[.]\(jpg\|jpeg\|png\|gif\)$' \
-exec mogrify -quality 85 -resize '500x500>' {} \;
zip -Duro ../tmp1.epub .
cd ..
rm -rf tmp
ebook-convert tmp.epub small.mobi

Isn't there a simpler way to tell calibre to convert the images to smaller sizes?

[HarryT]

Moved to the Calibre forum.

[kovidgoyal]

choose an output profile in calibre with a small screen size, or use the compress_news_images parameter in the recipe itself.