Over time, several people have inquired about the differences between the "Delete Mailbox" and "Remove Exchange Attributes" functionality in Exchange 2000/2003. Note: The Remove Exchange Attributes option only appears in the Exchange Tasks wizard within the Active Directory Users and Computers snap-in when the Advanced Features option is selected within the MMC console.
Seeing that I did not find much written about it, here is what I have learned.
This functionality was originally added in Exchange 2000 SP2. It was added to allow administrators the ability to forcibly remove Exchange attributes from a recipient object. This is useful in the following scenarios:
You use the ADC service and notice that some of your Exchange attributes are being incorrectly matched to the an Active Directory user object.
The mailbox for an Active Directory user points to an Exchange 200x server/database that no longer exists.
As part of the process to reconnect mailboxes after a disaster recovery operation.
Fundamentally, this is how it works:
If the object is a mailbox enabled user with a valid mailbox, then there is little difference between running these two options to delete the mailbox. Obviously, the "Delete Mailbox" option will be available only if there IS a mailbox (so a distribution list would have a "Remove email address" option instead).
The "Remove Exchange Attributes" option is available for ANY type of recipient object, mail enabled or not. This option is extremely useful when there is a need to "clear" the attributes in case that some of them were damaged or not valid for some reason. Let's say there is a mailbox enabled user that had some of his attributes changed by some process, and because of that, you cannot use the "Delete Mailbox" option. You can always run "Remove Exchange Attributes" to "clear out" the values so you can start fresh with mailbox enabling that user again.
Remove Exchange Attributes removes the following attributes as long as they actually exist as available attributes of that schema object:
autoReplyMessage (ILS Settings)
folderPathname (Outlook Web Access Server)
homeMDB (Exchange Mailbox Store)
mail (E-Mail Address)
msExchHomeServerName (Exchange Home Server)
proxyAddresses (Proxy Addresses)
In addition to removing the attributes above, the Delete Mailbox option also removes the mailbox information from the dsaccess cache. Note that this actually leaves the mailbox in place with the expectation that the mailbox cleanup task will take care of it at the appropriate time. So the mailbox is actually NOT deleted (purged) from the Information Store as part of this process. Although it will be purged by the mailbox cleanup task later, or as specified by the "Deletion settings" for mailboxes on the database's Limits tab in ESM.
So long story short, these two tasks can be viewed as redundant at times, as long as everything is OK and goes as expected. However, in cases where you are troubleshooting a problem and need to "clear" the attributes of objects (that might not have a full set of attributes so the "Delete mailbox" or "Delete email address" tasks might not be available) the "Remove Exchange Attributes" task is your friend.