winsock wont login

i am using winsock to connect to an ISP and sending email from VB6.
Winsock logs into one ISP & sends email OK, but not others. I get a 'connection forcefully terminated' message back from winsock after the .connect, from one ISP and just a logoff from another ISP.

I am doing all the standard stuff:

with winsock1
.localport =0
.protocol = sckTCPProtocol
.remotehost = "blaablaa.net.nz"
.remoteport =25
.connect

then wait for response of 220
then .senddata , etc




Anyone with Any ideas?

Some ISPs require you to be logged on to their network to access their mail servers.

Yeah, they check your IP address. It's so their mail servers can't be used to relay spam.

yes I have already logged into the ISP using my email account name/password.
I can mess up the hostname and get a 'host not found' error message, so I am close to connecting to the mail server....