Boswell's Q&A

Programmed to Reply

Configuring Exchange 2003 automated replies to internal and external e-mail accounts.

• By Bill Boswell
• 02/01/2005

We implemented an automatic reply on a public folder using your steps and it works fine for users in our Exchange organization. But it does not work for users from the Internet such as Yahoo or some other sender.

Any thoughts on why this might be the case?
— Melanie

Melanie: For readers who haven't ever tried to send e-mails to an Exchange 2003 (or Exchange 2000) public folder, there are a couple of configuration changes that must be made to get a satisfactory customer experience.

First, although every MAPI public folder is mail-enabled by default, the standard configuration hides the folders from the GAL. This encourages users to access folders via the Public Folder interface in Outlook rather than simply sending a message to the folder. In this default configuration, it's possible to send a message to a public folder using its SMTP mail address, such as [email protected].

But, to make it more convenient for users, you can let the folder appear in the GAL. Do this by opening the Properties window for the public folder in Exchange System Manager (ESM) and selecting the Exchange Advance tab. Uncheck the Hide From Exchange Address Lists option and click OK to save the change. In a few minutes, the Recipient Update Service will mark the corresponding Public Folder object in Active Directory with a Global Address List flag. At that point, users will see the folder in the GAL when they click the To... button in Outlook.

Whether or not you want to show the folder in the GAL, before Internet users can send mail to the folder, you have to make a small permission change. This is because Internet mail arrives via Simple Mail Transfer Protocol (SMTP), not MAPI. SMTP message traffic does not carry authentication credentials. In other words, Internet mail arrives "anonymously."

Standard public folder permissions do not allow anonymous postings. To permit Internet users to send mail to a Exchange public folder, you must change the MAPI permissions on the folder to give Contributor permissions to Anonymous. This can be done in ESM or in Outlook, if you have sufficient privileges. If you use ESM, open the Properties window for the folder, select the Permissions tab, click Client Permissions, then change the permission for Anonymous. You may need to add Anonymous to the list using the Add button. If you use Outlook, get access to the permission list by opening the Properties window and selecting the Permissions tab.

Okay, we've now caught up with Melanie. We have a public folder that accepts incoming e-mail from Internet users. We can configure an automated reply via the Folder Assistant as I described in in my ""Auto Babble" article and test it using an Exchange account. If everything is configured correctly, a MAPI sender will get an automated reply. But when you test the automated reply by e-mailing from an outside account, the sender will not get an automated reply.

Here's why: Exchange knows that spammers target mail to corporate e-mail users. Exchange does not want to give spammers a clue that a particular user is a "live" account, so it blocks all forms of automated replies—including out-of-office replies and automatic forwarding—to senders that are outside the Exchange organization.

To allow one or more of these automated replies to occur, go to the Global Settings icon in ESM, drill down to the Internet Message Format and open the properties of the Default format. Select the Advanced tab. Put a checkmark next to Allow Automatic Replies and click OK to save the change.

At this point, if you send a message to the public folder from an Internet account, you should get a reply.

I don't necessarily recommend that you make this change, because it would allow all automated replies to go to the Internet, which might increase the amount of spam you receive. But with the current billion-to-one ratio of spam to ham in the typical corporate message stream, you might not even notice the increase.