fsockopen() on port 23, 25, 110..

hello, I'm trying to connect to a remote host via a socket on port 23 (telnet port), but I can't get this to work.. (though telnetting to that host/port works fine) the only fsockopen() I can get to work is on port 80 (e.g. as shown in the example in php manual), I tryed also port 25,110 etc. on my mail server with the same result: the script hangs up on the fgets() , socket blocking or not.. anybody succeed in a similar task? I looked in mail archives on marc.theaimsgroup.com, www.geocrawler.com and the only thing I found is that many had this problem.. I couldn't find RFCs on telnet protocol, but I know those for SMTP/POP3, nonetheless fsockopen() doesn't work, while telnetting does.. I'm on win NT4 sp5, apache1.3.12, php4.0.0 (but the same goes for 4.0.1pl2 & 3.0.16) Thank you very much Giuse