I believe Apple just doesn't block it. It by default downloads all pixels (and images) for all emails so the sender cannot know if and when the reader actually

I believe Apple just doesn't block it. It by default downloads all pixels (and images) for all emails so the sender cannot know if and when the reader actually opened it. It will by default show 100% open rate. But, won't it be a problem? like some malicious actor could send lots of emails with 10s of MBs of image embeds and if Apple Mail automatically downloads it, then the storage will unnecessarily fill up. Is there a countermeasure to it which Apple has mentioned?