Updated from 2000 to XP, now I have problems

[Sherry]

As stated in the subject I updated from Office 2000 to
Office XP. I thought all the information in Outlook
would stay the same, but the information regarding the
different email accounts did not. For a while after I
put all the information back in, email address, username,
password, POP3 and SMTP info, it would not send or
receive. Now it will only send. Is there something
hidden that needs to be changed? I have checked and
double checked the account information. Please help, I
am very confused.
Thanks in advance!