Trying to help a friend who is running XP SP3 Home, and Office 2003.

In Outlook 2003, she has roughly 350 contacts and needs to send
periodic newsletters to each of them. She created 7 distribution lists
of 50 recipients each, and places one distro list in the BCC field
before sending. Her ISP suggested 50 recipients as a safe number, and
suggested waiting an hour between each send event to avoid the ISP's
spam filter. So far, so good. That worked fine for several months.
She uses her ISP's POP3 and SMTP mail servers, not Exchange/IMAP.

That computer died with a small puff of smoke and they decided to
place another XP Pro SP3 Home PC into service. She rescued the hard
drive from the dead computer and attached it to the new computer
externally via USB. In Outlook 2003 on the new computer, she selected
the Contacts window and Imported the contacts (and distribution lists)
from the rescued hard drive. Everything looks good - the Contacts
window shows all of the contacts, and the distribution lists are
present. Opening each DL shows that the email addresses are present
and look good.

THE PROBLEM: when she tries to send her newsletter to a distribution
list, the distribution list is silently stripped off and the email is
only sent to the address (her own) that was manually entered in the TO
field. She enabled Outlook Logging but it doesn't show any errors or
anything useful. Opening the item in the Sent folder shows that the
BCC field is empty.

Is there a known problem with using distribution lists that were
created on another PC and then imported? Does she have to delete her
distribution lists and recreate them?

Char Jackson