Is it possible to sort iOS Mail.app by size? How can this be done, because it's default ordered by sent date. I'd like to remove the biggest mails from my iPhone.
You can try this free app from iTunes store.
Find big emails in your Gmail to get your space back!
search mail by size allows find big mails, sorting and filtering mail by the size of email attachments (largest to smallest) and allows sending selected email messages to the GMail web trash folder. The application can sort thousands of email messages in just a few seconds.
Disclaimer: Have not tried it my self.