It is assumed that Eudora 3.X is being used, and while the comments were written with the Macintosh version in mind, most of the recommendations can be used in Eudora for Windows. Not doing so will result in the same dialog box being displayed the next time you check mail. Memory is tight. The most likely condition is that there is insufficient memory allocated to Eudora. Repeat this process if you get the message again.
Memory is tight.
You may need to close some windows, clean up your In, Out, and Trash mailboxes, or increase Eudora's memory size. Follow the instructions for Compacting Eudora mailboxes . Eudora uses memory for the In, Out, and Trash mailboxes as well as for displaying any open mailbox. No memory is used for closed mailboxes. If the mailboxes that you keep open are large, use Transfer to move some of your old messages to a separate mailbox that you do not keep open.