What mail service are you using?
Are you using a mail client (e.g. Outlook Express) to access the mail,
or just the mail service's web access?
If you are using a mail client, it could have settings to stop the
messages. For example, Outlook Express has the option via message rules
to not download or delete from the server, messages over a given message
If you anti-virus is scanning e-mail, it might be deleting the messages.
Or the messages may be larger than your mail service allows.
Mike - http://www.yqcomputer.com/