At which point do you get those errors? When connecting to the SMTP servers?
Yes - the response would come back quoting my old ISP address for some reason (old system prefs buried somewhere?). I re-installed it on another drive using another OS (10.5) and it's ok now.
However, I'm still having problems with spam filters as my outgoing server has the same address as the incoming ( POP rather than SMTP) one! I know this is down to my ISP rather than Email Verifier...
Thanks for your help.