I was helping someone a couple of days back on his problem with his Exchange Server 2003. This guy was running into a problem where users in his organization were able to send their emails to their personal email addresses using an automatic forwarding rule in outlook though the “Allow automatic forward” option was deselected at his Exchange Server 2003 Organization level. It was certainly not really very hard to suggest him to change the value of attribute msExchRoutingAcceptMessageType to 25 which fixed his problem. Yet, it would be really a fun to know how does Active Directory determine what to be allowed and what not to be when it is based on a numeric value? This is a small try to share my findings about it. So, when you look at the following picture you will notice there are some checkboxes selected and some are not. Based on these selected check boxes the value of the attribute msExchRoutingAcceptMessageType.
Now, what is value for each of these check boxes and how it varies? Take a look at below table:
|Check Box Selected||Value|
|Allow out of office responses||1|
|Allow automatic replies||2|
|Allow automatic forward||4|
|Allow delivery reports||8|
|Allow non-delivery reports||16|
|Preserve sender’s display name on message||NA|
So, when 1st and 2nd check boxes are selected the value of attribute msExchRoutingAcceptMessageType becomes 3. In simpler terms it would be simple addition of numbers based on the above table. The last option is “Preserve sender’s display name on messages” is not relate to these values. Attribute msExchRoutingDisplaySenderEnabled stores the value of it and works on a Boolean values of “TRUE” or “FALSE”.
Well, text and picture above is pretty clear and explains the things if you understand a little of AD and Exchange but where do I locate these attributes and their values? Open ADSIEDIT.msc and browse to the location below and open the properties dialog box:
CN=Default,CN=Internet Message Formats,CN=Global Settings,CN=<Org Name>,CN=Microsoft Exchange,CN=Services,CN=Configuration
Note: above location may change according to your customized settings.
Even before you go ahead follow this blindly and change the settings per your requirement, do take a look at your Active Directory health and replication as well. Exchange may not be able to contact AD for the correct information to read and hence allows the automatic forwarding to internet or does not apply the restrictions mentioned above.