[Dottore]

Thank you to everyone for your help - particularly Scott. I very much appreciate it.

I wish I had the last 12 hours of my life back though - but everything got sorted out in the end.

After having a series of ISP tech support guys telling me that either I had the SMTP settings wrong, or there was a software problem that I needed to take up with Apple, I finally got hold of a tech support guy - who as Scott suggested - checked whether my dad's email account might be corrupt on their server - and it was!

Joe: you also got this right.

Long story short, the ISP deleted the old account and we set it up again and everything now works just fine.

It's a long weekend here, and sensible advice is very thin on the ground. It speaks volumes for this little community (PPOT) that I was able to sort out this very annoying problem by seeking advice from the people on this board. Thank you again!

Scott - I owe you.

Cheers, Mark

PS: And I'm sorry to have to disappoint those of you who thought this was a Mac problem. ;-)