Multi-Valued Custom Attributes

As I mentioned in my previous post, Exchange 2010 SP2 introduces “multi-value custom attributes”. But what exactly does this mean? Basically, now there are 5 new custom attributes that can hold more than one value: ExtensionCustomAttribute1 to ExtensionCustomAttribute5, which can now hold up to 1,300 values each! Why do we need to store more than 1 value when we have 15 CustomAttributes?! Well, you might want to save in ExtensionCustomAttribute1 all the times you increased the user’s mailbox or all the databases you moved the user from/to, etc... I’m sure someone will come up with a good use for them!

If we compare CustomAttributes with ExtensionCustomAttributes, we can see that the new ones are stored in an array to allow for multiple values:

These parameters are used by the following cmdlets:

• Set-DistributionGroup
• Set-DynamicDistributionGroup
• Set-Mailbox
• Set-MailContact
• Set-MailPublicFolder
• Set-RemoteMailbox

As you can see from this list, you can use attributes with Distribution Groups, Mailboxes, Contacts, mail enabled Public Folders and Remote Mailboxes.

There are several methods of saving data in these attributes. First, let’s look at how we can set new values:

Now let’s add values to the existing ones. Here we have two options:

1. Using the “normal” method that most administrators are used to;
2. Using the Add functionality introduced with SP1.

As you can see, the second method is much easier! A very welcome improvement.

To remove, we can also use both methods but, again, the easiest one is the second:

Hope this helps and please let me know if you plan to use them and for what!