On Tuesday January 31 2017 14:04, you wrote to Wilfred van Velzen:
WV>> My system delivers mail as soon as it is available for your WV>> system. So there is no need for you to poll, because there won't WV>> be any mail to deliver at that moment...
TK> It is always good to poll every link to see if they are alive or not.
Contaminating someone's log by making useless polls every 30 minutes may be considered annoying if it goes against the express wishes of the subject.