Eudora prevents Intel Mac Sleep

Having Eudora "running" prevents the computer from sleeping, although the display does.
Roger wrote on :

Hi-

I'm using Eudora 6.2.4 (paid) on an Intel 10.4.8. Having Eudora "running" prevents the computer from sleeping, although the display does.

Quitting Eudora allows sleep. Manually selecting sleep from the Apple menu works. Eudora only checks for mail every 60 minutes, while the Energy Saver is set up to sleep in 30 minutes. I've found several reports of this on other forums (including this occurring with Eudora set up for only manual checks), but no solutions.

Can anyone assist with a cure or work around?

Thanks in advance.

-- Roger