Hi, I have sent different missions, some of them were approved and some were not. But I never received an e-mail about it, so I can't realize on what is wrong in my rejected mission proposals.
Thanks for reaching out, @ColoWixtor! Please check your email's spam folder to make sure that the notifications are not being sent there. If you are unable to find the notifications it could be possible that they are not sent successfully. It may occur if Ingress sync is not active.
If you are on android: On Android, to confirm, go to Settings > Accounts & sync >Google and select your email.
On iOS: Make sure that you are not closing/exiting Ingress immediately after sending Portal submissions.