I resigned from the UN with my nation, then (since I don't do multying) I applied to join the UN with my other nation. Apperantly they don't accept the same e-mail adres. It's not a problem to me, I just used another adres, but why can't I use my old one?
ps: this goes in technical
it could have been set up by the admin to block nations from multying
You have to wait for the serve to remove the "UN Member" Image and the UN page to say "West-Flanders is not a Member of the UN" and have the "Apply to Join" button and then wait twelve hours before you can use the same email address again.
Qaaolchoura is correct.