Contrary to the post of another user below, Qualcomm will not be releasing the existing commercial code of Eudora to open source but will instead be using the existing code base of Mozilla Thunderbird and branding it under the Eudora name. At least this is the case according to articles from reputable sources.

As a result, Eudora, as we have known it, will cease. No further development will take place. It would be better if Qualcomm did in fact release the Eudora source code into open source -- since it has no appetite for the product anyway, (and this has been clear for a number of years and this decision is late in coming). But for some reason, Qualcomm will retain the existing code and just graft the Eudora name upon another code base -- again, according to sources.

The fact is that Eudora has languished and suffered from neglect for a number of years now. A pity, really.