When Exchange is installed, the default configuration is to block any user defined rules that would forward their email to an external account. (They can still forward emails manually.)
Why might someone want to define a rule to forward to an external account? One reason is that if someone is out of the office forwarding emails to another account (such as on a blackberry) may be a convenient way of keeping in touch.
Why is this blocked by default? The reason often quoted is that it makes the system vulnerable to email looping. For example, if someone defines a rule that forwards all of their email to home, and then on their home system defines a system for forwarding all their email to work, then the system will be forever forwarding emails. Consider this carefully before allowing emails to be forwarded (by rule).
To enable forwarding by rule:
- Log on to the server running exchange server.
- Run “Exchange System Manager”.
- Expand “Global Settings”.
- Click on “Internet Message Formats” to highlight it.
- In the right hand window pane, double click on “Default” to open its properties.
- On the “Advanced” tab, check “Allow automatic forward”.
- Click [OK] to save.