The issues with these browsers/email programs is not that they are non-free
as they aren't. It is that they are linking to non-free software and by
associate the project might be perceived as recommending non-free software.
Essentially SeaMonkey is ok if you don't tell others you are using it or
click the links to or use the non-free components.
:)
Anybody who is really really really well informed want to chime in?
I think the fact we are talking about it is more of a problem than if you
were to actually use just the free bits.