Hi Jonathan,
>Yes: admin@cobatco.com, to whom I was trying to respond. But I worded
>my question badly - what I meant was: why on earth should their machine
>think that I am a Polish spammer ? The IP address is in one of the
>static blocks administered by my (UK) ISP.

They may be using a "blacklist" to block SMTP connections from
Poland. That list has the wrong geographic information for your IP
address block.