Eudora will download all the message that can fit on your disk. You will get a message stating that the disk is full. You will have to make another disk to collect the rest of your mail. Once you have checked your mail it has been removed from the SFSU servers. It is recommended that you not use Pine to read your mail if you are using Eudora.
Several problems occur when going back and forth between the two different mail programs.
Here are some basic steps you can take to reduce the chances of losing your mail. Always carry your disk in a disk case. Backup your disk to another floppy or to a hard drive if you have access to one.