Configure a Catch-All Mailbox

Makale
07/23/2014

Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

You can configure transport rules on Edge Transport servers to copy or redirect messages received by your organization to the catch-all mailbox. A catch-all mailbox is typically a mailbox in your organization used to collect all the e-mail messages sent to your organization. Depending on your preferences, the catch-all mailbox may receive all messages or only messages sent to mailboxes that don't exist.

To configure a catch-all mailbox, you must perform the following steps:

Create a mailbox.
Disable recipient filtering.
Configure a transport rule to copy or redirect messages to the catch-all mailbox.

Looking for other management tasks related to mailboxes? Check out Managing Mailbox Servers.

Prerequisites

Before you disable recipient filtering (as required in step 2), you should understand the benefits of running the Recipient Filter agent and understand what features depend on it. For more information about the Recipient Filter agent and how it helps reduce the effect of spam, denial of service attacks (DoS), and other threats, see Understanding Recipient Filtering.

Note

Recipients are resolved before messages pass through the Transport Rules agent on Hub Transport servers. Therefore, transport rules on Hub Transport servers can't be used to copy or redirect messages to a catch-all mailbox.

Step 1: Create a mailbox

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "User mailboxes" entry in the Mailbox Permissions topic.

You must create a mailbox to receive the messages that are copied or redirected to it by transport rules. Because the messages delivered to the new mailbox may contain sensitive information, restrict access to the mailbox.

Create the catch-all mailbox. For details, see Create a Mailbox.
Complete one or both of the following, depending on the volume of messages delivered to the mailbox:
- Increase the mailbox quota limits. For more information, see Configure Storage Quotas for a Mailbox.
- Configure messaging records management (MRM) to automatically remove messages from the mailbox that are older than a configured age. For more information, see Create a Retention Tag and Create Managed Content Settings.
After you create the mailbox, note the SMTP address assigned to the mailbox.

Step 2: Disable recipient filtering

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Anti-spam features" and "Anti-spam features – Edge Transport" entry in the Transport Permissions topic.

You must disable recipient filtering on each Edge Transport server that you want to configure transport rules to copy or redirect messages to a catch-all mailbox. You must do this because messages pass through the Recipient Filter agent before passing through the Edge Rule agent, and the Recipient Filter agent will reject messages addressed to mailboxes that don't exist.

Use the EMC on an Edge Transport server to disable recipient filtering

Open the EMC on the Edge Transport server where you want to create the transport rule.
In the console tree, click Edge Transport.
In the work pane, click the Anti-spam tab, and then select Recipient Filtering.
In the action pane, click Disable.

Use the Shell on an Edge Transport server to disable recipient filtering

This example disables recipient filtering.

Set-RecipientFilterConfig -Enabled $false

For detailed syntax and parameter information, see Set-RecipientFilterConfig.

Step 3: Configure a transport rule to copy or redirect messages to the catch-all mailbox

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Transport rules" entry in the Messaging Policy and Compliance Permissions topic.

After you create a mailbox to accept messages and you disable recipient filtering, you must create a transport rule to copy or redirect messages to the catch-all mailbox. You must configure this transport rule on each Edge Transport server on which you want to copy or redirect messages.

Your organization's requirements should determine whether you copy messages to the catch-all mailbox or redirect messages to the catch-all mailbox. The differences between the two actions are as follows:

When a message is copied to the catch-all mailbox (using the Cc line or Bcc line text box), the message also continues to the original recipient. If the original recipient doesn't exist, the sender receives a non-delivery report (NDR).
When a message is redirected to the catch-all mailbox, the message doesn't continue to the original recipient. The message is sent only to the catch-all mailbox. If the original recipient doesn't exist, the sender doesn't receive an NDR.

You should also configure the except when the text patterns appears in any recipient address exception to avoid copying or redirecting messages to the catch-all mailbox for SMTP addresses that already exist in your organization. This exception uses regular expressions to prevent the transport rule from copying or redirecting messages to the catch-all mailbox if the SMTP address exists in your organization. You must manually configure the exception with the SMTP addresses in your organization and enclose each SMTP address with the ^ and $ pattern strings.

For more information about regular expressions, see Regular Expressions in Transport Rules.

Important

A message sent to your organization won't be copied or redirected to the catch-all mailbox if one or more SMTP addresses are included in the message recipients and are configured on the transport rule exception. This is true even if one or more of the SMTP addresses on the message doesn't exist in your organization.

Use the EMC to configure a transport rule to copy or redirect a message to the catch-all mailbox

Open the EMC on the Edge Transport server on which you want to create the transport rule.
In the console tree, click Edge Transport.
In the result pane, click the Transport Rules tab, and then in the Actions pane, click New Transport Rule.
In the Name field of the Transport Rule wizard, type the name of the transport rule.
If you have notes for this rule, in the Comments field, type the notes.
If you want the rule to be created in a disabled state, clear the Enable Rule check box. Otherwise, leave the Enable Rule check box selected. Click Next.
In the Step 1. Select Condition(s) box, select the from users that are inside or outside the organization check box.
In the Step 2. Edit the rule description by clicking an underlined value box, click inside the organization.
In the From scope list, select Outside the organization, and then click OK.
If you want to add conditions, do so now. After you configure all the conditions, click Next.
In the Step 1. Select Action(s) box, select copy the message to addresses if you want to copy messages to the catch-all mailbox. Select redirect the message to addresses if you want to redirect messages to the catch-all mailbox. Don't select both actions in the same transport rule.
In the Step 2. Edit the rule description by clicking an underlined value box, click addresses.
In the Specify recipients dialog box, type the SMTP address of the catch-all mailbox in the E-mail addresses of recipients box, click Add, and then click OK.
If you want to configure additional actions, do so now. After you configure all the actions, click Next.
In the Step 1. Select Exceptions if necessary box, select the except when any recipient address matches text patterns check box.
In the Step 2. Edit the rule description by clicking an underlined value box, click text patterns.
In the Text patterns box, type the SMTP addresses of existing mailboxes in your organization. Enclose each SMTP address with the ^ and $ pattern strings. For example, if the SMTP address is david@contoso.com, enter: ^david@contoso.com$. After you enter each SMTP address, click Add. When you have finished, click OK to close the window.
If you want to configure additional exceptions, do so now. After you configure all the exceptions, click Next.
Review the Configuration Summary. If the configuration of the new rule is satisfactory, click New, and then click Finish.

Use the Shell to configure a transport rule to copy or redirect a message to the catch-all mailbox

Before you begin, you must be familiar with how to create a transport rule using the Shell. For more information, see "Use the Shell to create a transport rule" in Create a Transport Rule.

To configure a transport rule to copy or redirect messages to a catch-all mailbox, you must configure the transport rule condition that directs the transport rule to apply the action only to messages sent from senders outside the organization. To do this, use the FromScope transport rule predicate together with the New-TransportRule cmdlet.

The following example configures a transport rule to copy messages from senders outside the organization to the catch-all mailbox:

New-TransportRule -Name "Catch-all Mailbox" -FromScope NotInOrganization -Actions RedirectMessage <Catch_All_Mailbox _Address>

Use the Shell to configure the transport rule condition to copy messages to a catch-all mailbox on an Edge Transport server

This example configures the transport rule condition to:

Select messages only from senders outside the organization.
Copy a message to the catch-all mailbox.
Specify the SMTP address of the catch-all mailbox.
Avoid copying messages sent to SMTP addresses that exist in your organization.
Create a transport rule that copies messages to a catch-all mailbox.

New-TransportRule -Name "Copy messages to catch-all mailbox" -FromScope NotInOrganization -CopyTo "catch-all@contoso.com" -ExceptIfAnyOfRecipientAddressMatchesPatterns "^david@contoso.com$", "^brian@contoso.com$"

For detailed syntax and parameter information, see Get-TransportRulePredicate, Get-TransportRuleAction, or New-TransportRule.

Use the Shell to redirect messages to a catch-all mailbox on an Edge Transport server