Wietse Venema:
> > Thinking that postfix
> > must wait to get that 220 message before trying to send any commands.
> > Anyone else had this kind of issue? I did notice when I do a telnet
> > SMTP session to that server from my workstation (a Windows machine)
> > I get the 220 message when it connects.
>
> Perhaps they have blacklisted your IP address, because it was sending
> spam or malware from an infected machine.
Another possibility is "security" software on the server itself
(reportedly, some anti-virus products mess with outbound SMTP).
Wietse
