My ISP reckons this is a known Outlook bug that should be fixed by office
Service Pack 3, but after a week of frustration, and doing what I am told, I
still get the following errors, 0x800CCC15, 0x8004210A, 0x8004210B. The Big
Pond webmail seems to work fine and all the e-mail account settings were
checked with the their technical support. I applies the registry change
recommended in the particular hotfix, but that made no difference. It was
working fine until a week ago, although it would send multiple copies of
300kb e-mails to addressees. The sending seemed to fail before the receiving.