But if it's some custom email server, it is possible that such pings are logged. If logged then the recipient could be notified. Since you don't control said server, the answer is thus maybe. That is, since there are some possible million email servers in the world, you know that each one could be different. While a ping was in the past tossed out, with all the spammers out there today, my bet is such is logged and a source that pings too much may get black listed.