Not sure if this helps but it could be that the NTL server already has you logged in on Computer No.1 and by trying to log in with Computer No2 or 3, its a security issue to disable access from more than one IP address??
Again,alternatively although I only use the one PC , I have 3 separate user accounts, the e-mail addresses are
[email protected]
[email protected]
[email protected]
but whenever any of us go into e-mail whichever goes first downloads ALL the "isp.com" e-mail irrespective of who it is for, maybe NTL has a similar issue whereby once its been downloaded, its gone??
If you cant solve it as an alternative, I suppose you could set up a different e-mail address for each pc (whether NTL or not) and use the mail rules to forward any mails received at PC No1 to those other addresses(bit long winded perhaps, but at least they would go through) ?
Never had NTL and no idea how its configured, so apologies if Im talking rubbish.