You create some recipients by using Exchange Management Console or Exchange Management Shell in a Microsoft Exchange Server 2010 or Exchange Server 2013 environment. Or, you enable some mailboxes to cloud by running the Enable-RemoteMailbox or New-MailUser cmdlet from a Microsoft Exchange Server 2013 on-premises environment.
The aliases of the recipients begin with one of the following combinations of lowercase characters followed by numbers or combination of numbers and letter "a" to "c":
For example, the alias is sa000c1 or s123456.
You create an email address policy and apply the policy to the recipients.
In this scenario, the email address policy does not generate the email addresses of the recipients correctly. For example, the secondary email address of the recipients is not generated.
This issue occurs because these aliases match a special pattern. Therefore, they are recognized as randomized proxy names incorrectly.
To resolve this issue, install one of the following updates in your environment:
2661854 Description of Update Rollup 2 for Exchange Server 2010 Service Pack 2
3135743 Description of Cumulative Update 13 for Exchange Server 2013
After you install the update, to have us enable the update for you, go to the "Fix it for me" section. If you prefer to enable this update yourself, go to the "Let me fix it myself" section.
Fix it for me
To enable this update automatically, click the Fix it button or link. Then click Run in the File Download dialog box, and follow the steps in the Fix it wizard.
Install the update that is described in Microsoft Knowledge Base (KB) article 2661854 or 3135743 before you run this Fix it solution.
This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
If you are not on the computer that has the problem, save the Fix it solution to a flash drive or a CD and then run it on the computer that has the problem.
Important Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.
For Exchange Server 2010
To enable the fix after Update Rollup 2 for Exchange Server 2010 Service Pack 2 is installed, change the following registry key:
Click Start, click Run, type regedit, and then press Enter.
Microsoft Exchange Server 2013 Enterprise, Microsoft Exchange Server 2013 Standard, Microsoft Exchange Server 2010 Enterprise, Microsoft Exchange Server 2010 Standard, Microsoft Exchange Server 2010 Service Pack 2