We are running 2003 domain and 2003 Exchange. We installed 2010 Exchange server and migrated a few users. What is happening is users email addresses are changing. Seems to be using First Initial Last name but when I open the Default Email Policy from 2010 I get the following error "Recipient policy objects that don't contain e-mail address won't be shown unless you include the IncludeMailboxSettingOnlyPolicy parameter in the Get-EmailAddressPolicy cmdlet". But the only thing that is defined inside the policy is 3 different domains with the default domain being the default nothing else is defined. If you try to open the policy from a 2003 server it tells you that it was created from a newer version and you cannot edit. When you run the following command
get-emailaddresspolicy "Default Policy"

I get the following response

Name                                    Priority                                RecipientFilter
----                                    --------                                ---------------
Default Policy                          Lowest                                  Alias -ne $null

Now if I browse AD using ADSI edit into the following

Configuration - Services - Microsoft Exchange - Our Domain - Recipient Update Services

I see 2 policies one that created from the 2003 servers and another one Enterprise Configuration which I think is the one that was upgraded. Should it show 2 policies there or only one.

So what I have noticed is after you set a users email address under 2010 or 2003 exchange it changes it to be first initial last name after about 20 minutes or so. Then we have to go in and change the alias and email address. A few times we found that it removed all the email addresses completely. The weirdest one was I removed the alias from my account and it was as though I didn't even have an email address. I went and searched for my mailbox and it showed nothing yet I could see all the attributes were still there except mailnickname which I added manually and set correctly. I cannot figure why it is changing the email addresses on it's own. Now if I go under 2010 EMC I look at the email address policy(there is only one the default policy) I see it shows as not applied. 

Anyone have any clue what is going on this is affecting all my users 2003 and 2010 because it is changing their email address and mail is getting returned because the email address does not exist unless I change it only to find 20 minutes later it is changed back. Any help would be appreciated.