my first offering is use screen
you do not mention which Linux Distro you use, so I can not advise how you install it
open a 'screen'
then your scp, optionally followed by && exit
scp file Server2 && exit
now detatch from screen with Ctrl+a ,d
that is Ctrl+a keycombo, then key d
you should now be able to logoff
when you log back on reattach to screen
if that fails, all went well
if not either the upload is still in progress or something went wrong.. you should see any error that occurred.