The solution is to delete those you no longer need, perhaps after archiving them if you think you may need them in the future. Remember, it’s not just documents, PDFs and photos that are sent as attachments, company logos and other images in email signatures are attachments too.
And if you get lots of attachments that can mean occupying quite a bit of space. Whether you download attachments or leave them on your mail server, they take up space somewhere.
Hence, to delete Mail storage on Mac, the easiest is to start with Mail attachments and junk mail. But that's far from true and doesn't take into account your downloaded messages and attachments. Now I know that my Mail takes up 724 MB of storage. Open the Apple menu > About this Mac > Storage > Manage. The storage Mail occupies consists of two parts: the Mail app itself and your user-created data. How to check the space Mail is taking upīefore you do anything, let’s investigate how serious your storage problem is. But here we'll try to trim down its size. It keeps you in the dark about the actual storage it uses and if left unchecked, Mail app may silently grow to an enormous size. The default macOS Mail app is an invisible space eater. But to help you do it all by yourself, we’ve gathered our best ideas and solutions below. So here's a tip for you: Download CleanMyMac to quickly solve some of the issues mentioned in this article.