I have the same issue but with Thunderbird - I cannot shut off the download graphics blocker. I've gone to Mozilla help - performed the recommended function and NOTHING changes (done this 3-4 times).
I find this feature to be a BIG pain in the backside. I would like a simple option (that works) to turn this 'protection' off as I do not in the slightest manner need to be protected from downloaded graphics (as I have a very good anti-virus program) and have no minors to protect from offensive graphics.
I plan on downloading Eudora for a test drive in the near futhre.