My email+messaging data is showing above 250 MB in Storage sense. I couldn't find any way to clean up the data. Is there any way? Deleting the messages from the email client doesn't affecting the data size.
In your email account settings you can choose for how long you want to keep your mails on your device. Change that to a lower value to get back some space. When you delete your mails make sure you also clear the deleted mails folder. Also, a single mail might be too small to be noticed by storage sense.