I recently had an opportunity to learn about an issue that I have not seen personally but I found it very interesting.

When you introduce Exchange Server in your environment, it extends Active Directory Schema and User Class is updated with additional attributes ms-Exch-Extension-Attribute-1 through ms-Exch-Extension-Attribute-15 among others.

These attributes allow you to store values that you can use for various reasons. Some applications are designed to make use of them as well.

The custom attributes are created as defined by Exchange setup routine.

Now the problem that I learned about is when you move a mailbox using Exchange 2007 tools. You may see an error: Custom Attributex is too long: maximum length is xxxx and the actual length is yyyy (where xxxx is wither 1024 or 2048) and yyyy is greater than xxxx.

You do not see this problem if you move mailbox from Exchange 2003 to Exchange 2003 for the same user that fails when you try to move to Exchange 2007 mailbox server.

The reason why you do not see this issue in Exchange 2003 is due to more stringent checks implemented in Exchange 2007 for mailbox moves and other tasks/functions.

I learned about this issue from Eric Norberg and am not going to reinvent the wheel. I will let you read full details of this issue and resolution here.

However, the summary of it is, if you have this issue, check the rangeUpper value of attribute listed in error. If the value is not 1024 for ms-Exch-Extension-Attribute-1 through ms-Exch-Extension-Attribute-10 or 2048 for ms-Exch-Extension-Attribute-11 through ms-Exch-Extension-Attribute-15, someone or something has modified the value after Exchange Server 2007 setup was run.

You can read more detail on this in Eric’s blog post mentioned above.

It is important to note that Schema edits of default Exchange and Windows objects or attributes and their default values is not a supported configuration.

Quote of the day:
Don’t worry about people stealing an idea. If it’s original, you will have to ram it down their throats. – Howard Aiken