Netscape 4 has a useful option that allows you to limit the size of messages it downloads.
Go to Edit | Preferences and select Disk Space from Mail & Newsgroups. Check the box next to Do not store messages locally larger than 50 K. 50 KB is the default value, which you can change.
With this option turned on, Netscape will stop downloading messages after 50 KB (or the value you chose). In the truncated message, you will find a link that allows you to fetch it in full length, or you can delete the message from the server and spare yourself the download.

