Why is my Manual e-mail sync setting ignored?

I just got a new BlackBerry Q10 and so far, I'm pretty satisfied with it. However, I'm on a tight data plan which I'd like to keep. I did set up my e-mail accounts and configured them to not sync automatically. I'd like to go to the e-mail account and press the 'Refresh' button to fetch new e-mails. However, it doesn't seem to work: usually, my phone recieves new messages before my laptop does. Why is this setting ignored? Is there any way to fix it?

Some specs:
BlackBerry Q10 SQN100-3
Software version: 10.3.1.600 (leak)
Mail provider: self-hosted e-mail server running Courier IMAP server, second self-hosted e-mail server running Dovecot e-mail server.

I have the same problem with my pop account, but our exchange seems to work....
Also when turning flight mode off when arriving a new country i receive new mails.

Regards Bob

/Bob 10.2.1.2941