Why the Bitmessage is no longer considered?
One thing is that it's python, which is not a big problem as with jython it should be not so hard to get it integrated into a java project, but a pure java solution would be more convenient. But that´s not the main reason...
I have not researched yet enough to discuss my skepticism regarding BitMessage in detail, but scalability, reliability and privacy are the areas where I am unsure. But as said, I need to investigate more to have a real opinion regarding those issues.
My impression of bitmessage is the same. A nice first pass, or proof of concept.
First major problem is that every node tries to decrypt every message on the network, this cannot scale. In fact, just having every node get passed every message can't scale either, even if it doesn't have to try to decrypt them all (I'm sure the effort needed to test a message to see if it's "for me" can be reduced).
The other major problem is that if your node is offline for a while, you can permanently lose messages. So you can't just integrate a bitmessage client into an app, the bitmessage process has to run continuously (or at least periodically).
And just in my casual use, it seems like the proof of work required by default is too small, I got spammed immediately. That's not a major issue though.
I'm not an expert but there do seem to be better overall designs, but hard to say since they haven't been implemented.
