This could be due to one of the following reasons:
- A configuration issue with IMAP or POP access
- Settings applied to incoming mail, such as a filter or forwarding
- Deliberate or accidental human action, or possibly a compromised account
If you are a Googlemail user (this includes those with ntlworld, virginmedia or sky email addresses) information and help can be found by clicking on the link below. The answers provided by Google can be applied to most internet service providers ie BT.