After carefully reading
I still haven't been able to get TBP working with my yahoo account. I tried it with my inbox.com email address and it worked fine.
I noticed some people in a posting said it doesn't need the extension yahoo-1-1-16.xpi. Was this for standard yahoo webmail or the PLUS! account. With/without xpi i don't seem to be able to get it to work.
It seems there is something not right with the settings and i'd be grateful to check with someone. I'm not sure that the incoming/outgoing servers should be "localhost".
In one posting (sorry can't find it) there were the following steps
Click File » New... » Acount
Choose Web Mail
I don't get a webmail option?