they called me back. i was on hold forever and my phone battery started beeping so i left another message. they called back again. evidently, every time i was deleting an email with attachments, the attachments were being saved by eudora. some 1700 of them, who knows how many viruses. avg found something and was trying to delete it but there wasn't any room for it. anyway, everything is happy now and eudora won't be saving attachments any more. thanks for all the suggestions.
oh, i forgot, my registration expired 4 days ago, but they gave me a free tech call anyway. yay eudora!