There may be a time when your emails aren't coming in or you cannot update your folder. You may have maxed out your storage on your email server. To resolve this issue, you will need to delete a significant portion of your emails. Once those are deleted, you will need to permanently delete them from the server, since they are still stored after your first delete, this is called a "soft delete".
Please look at the article above and follow the steps to delete your email messages permanently.
