You have an Exchange Server 2013 organization named adatum.com. The organization contains two
servers named EX1 and EX2 that are configured as shown in the table.

Both servers are members of a database availability group (DAG). EX1 has the active copy of a
database named Database1. Several users who have mailboxes in Database1 discover that all of
their outbound email messages remain in their Drafts folder when they use Outlook Web App. You
need to ensure that the email messages are delivered. What should you do?

A.
On EX2, retry the message queues.

B.
On EX1, start the Microsoft Exchange Mailbox Transport Submission service.

C.
On EX2, start the Microsoft Exchange Mailbox Transport Submission service.

D.
On EX1, retry the message queues.

Explanation:
In Microsoft Exchange Server 2013, mail flow occurs through the transport pipeline. The transport
pipeline is a collection of services, connections, components, and queues that work together to
route all messages to the categorizer in the Transport service on a Mailbox server inside the organization.

The Transport service on a Mailbox server
Every message that’s sent or received in an Exchange 2013 organization must be categorized in the
Transport service on a Mailbox server before it can be routed and delivered. After a message has
been categorized, it’s put in a delivery queue for delivery to the destination mailbox database, the
destination database availability group (DAG), Active Directory site, or Active Directory forest, or to
the destination domain outside the organization.

The Transport service on a Mailbox server consists of the following components and processes:
SMTP Receive When messages are received by the Transport service, message content inspection is
performed, transport rules are applied, and anti-spam and anti-malware inspection is performed if
they are enabled. The SMTP session has a series of events that work together in a specific order to
validate the contents of a message before it’s accepted. After a message has passed completely
through SMTP Receive and isn’t rejected by receive events, or by an anti-spam and anti-malware
agent, it’s put in the Submission queue.
Submission Submission is the process of putting messages into the Submission queue. The
categorizer picks up one message at a time for categorization. Submission happens in three ways:
Through an SMTP Receive connector.
Through the Pickup directory or the Replay directory. These directories exist on the Mailbox server.
Correctly formatted message files that are copied into the Pickup directory or the Replay directory
are put directly into the Submission queue.
Through a transport agent.
Categorizer The categorizer picks up one message at a time from the Submission queue. The
categorizer completes the following steps:
Recipient resolution, which includes top-level addressing, expansion, and bifurcation.
Routing resolution.
Content conversion.
Additionally, mail flow rules that are defined by the organization are applied. After messages have
been categorized, they’re put into a delivery queue that’s based on the destination of the message.
Messages are queued by the destination mailbox database, DAG, Active Directory site, Active
Directory forest or external domain.
SMTP Send How messages are routed from the Transport service depends on the location of the
message recipients relative to the Mailbox server where categorization occurred. The message could
be routed to the Mailbox Transport service on the same Mailbox server, the Mailbox Transport
service on a different Mailbox server that’s part of the same DAG, the Transport service on a Mailbox
server in a different DAG, Active Directory site, or Active Directory forest, or to the Front End
Transport service on a Client Access server for delivery to the Internet.
Retry a Message Queue
When a transport server can’t connect to the next hop, the delivery queue is put in a status of Retry.
When you retry a delivery queue by using Queue Viewer or the Shell, you force an immediate
connection attempt and override the next scheduled retry time.
If the connection isn’t successful, the retry interval timer is reset. The delivery queue must be in a
status of
Retry for this action to have any effect.
Use Queue Viewer in the Exchange Toolbox to retry a queue Click Start > All Programs > Microsoft
Exchange 2013 > Exchange Toolbox.
In the Mail flow tools section, double-click Queue Viewer to open the tool in a new window.
In Queue Viewer, click the Queues tab. A list of all queues on the server to which you’re connected is
displayed.
Click Create Filter, and enter your filter expression as follows:
Select Status from the queue property drop-down list.
Select Equals from the comparison operator drop-down list.
Select Retry from the value drop-down list.
Click Apply Filter. All queues that currently have a Retry status are displayed.

Select one or more queues from the list. Right-click, and then select Retry Queue. If the connection
attempt is successful, the queue status changes to Active. If no connection can be made, the queue
remains in a status of Retry and the next retry time is updated.
Resubmit messages in queues
Resubmitting a queue is similar to retrying a queue, except the messages are sent back to the
Submission queue for the categorizer to reprocess. You can resubmit messages that have the
following status:
Delivery queues that have the status of Retry. The messages in the queues can’t be in the Suspended
state.
Messages in the Unreachable queue that aren’t in the Suspended state.
Messages in the poison message queue.
OWA DRAFTS FOLDER
http://thoughtsofanidlemind.wordpress.com/2013/03/25/exchange-2013-dns-stuck-messages/
OWA clients automatically capture copies of messages as they are being composed and store them
in the Drafts folder. When the user issues a sent command, the Mailbox submit agent (running
within the Store driver) takes over and processes the outbound message by giving it to either the
Transport service running on the same mailbox server or to the Transport server running on another
mailbox server. The connection is made via SMTP.
Messages stay in the Drafts folder until they are successfully sent by being processed by the
transport service.
At this point, items are moved into the Sent Items folder. OWA 2013 behaves in the same way as
OWA 2010 –nothing has changed in the way that messages are held in the Drafts folder until
dispatch. What might account for user descriptions of items being “stuck” is when a problem occurs
somewhere in the transport pipeline that prevents outbound messages being processed.
For instance, items will remain in the Drafts folder if the Store cannot pass them to the transport
system. If the transport service is not running on any available server or the mailbox transport
service is not running on the mailbox server that hosts the active database for the user’s mailbox,
items will stay in the Drafts folder until the services come online and Exchange is able to process
outbound items.
NOT A C
Active copy of a database named Database1 (EX1) not on EX2
NOT D
Messages stay in the Drafts folder until they are successfully sent by being processed by the
transport service
B
Resubmitting a queue is similar to retrying a queue, except the messages are sent back to the
Submission queue for the categorizer to reprocess.
Messages stay in the Drafts folder until they are successfully sent by being processed by the
transport service If the transport service is not running on any available server or the mailbox
transport service is not running on the mailbox server that hosts the active database for the user’s
mailbox, items will stay in the Drafts folder until the services come online and Exchange is able to
process outbound items.