We have Exchange 2007 (SBS 2008) which has been working without any issues for several months.
Today emails are being received, however, emails from external domains the email bodies are blank, no content at all. We are not running any email filtering software and I do not think this is a client antivirus problem, as emails are blank when viewing on OWA.
Nothing in the event logs shows anything awry. We have tried restarting all the main exchange services.
Just added an email account, via the pop3 connector. It downloaded email to an account without any problems at all.