still you can try with soup tracing i guess
set MIDORI_DEBUG=headers
and then run midori (-p private should work too) from cli, maybe you spot something obviously wrong on those mail sites.
Would be nice to try those as well with current version of webkitgtk on windows but it is unfortuately very unstable at the moment (you would need to basically disable js to test anything) so not sure if it would be that helpful here
still you can try with soup tracing i guess DEBUG=headers
set MIDORI_
and then run midori (-p private should work too) from cli, maybe you spot something obviously wrong on those mail sites.
Would be nice to try those as well with current version of webkitgtk on windows but it is unfortuately very unstable at the moment (you would need to basically disable js to test anything) so not sure if it would be that helpful here