lots of options.
check the file size to see what you are moving.
outlook express is probably 10 years ago for me. from memory I think size is in properties. may well be bigger than your 2GB drive capacity ?
I use one drive but not sure about data costs etc for cloud etc.
you need spx files for windows 10.
search on google for
dbx to spx conversion.
converting to Thunderbird is my option but may be others to consider.