I get more than 200 e-mails a day and I can get up to 250 to display by scrolling down and hitting update, but once it's at 250, it won't load anymore. I can't find a way around this in any of the settings but I keep hoping there is a way.
If you're using newer IMAP protocol you can search for and display any email on your email server. This cannot be done if you're using the legacy POP protocol, though.