"Do not deliver before" Behavior Doesn't Work as Expected in Outlook Cached Mode

Friday, May 25, 2007
Users sometimes schedule delivery of an email for a later date or time.

For Outlook 2000, there were two different options: Deferred Send (Outlook handles it) and Deferred Delivery (the Exchange server handles it). If a message is configured for Deferred Send, it will stay in the user's Outbox until the scheduled time. Outlook then submits the message to the Exchange Information Store and the message is delivered. If a message is configured for Deferred Delivery, Outlook will immediately submit the message to the Exchange Information Store and the Exchange server will hold the message until the scheduled time. With Deferred Send, Outlook must be running to send the message and the user can edit or remove the message before it's delivered. With Deferred Delivery, Outlook does not have to be running and the user cannot edit or remove the message before it's sent.

Microsoft merged the two features together for Outlook 2003/2007. The only option available in these versions is "Do not deliver before". If this is configured the message will stay in the user's Outbox, but Outlook does not need to be running to deliver it. By keeping it in the Outbox, the user is able to edit or remove the message before it's sent. However, if the user is configured for Exchange Cached Mode, Outlook MUST be running for delivery of message to occur. http://support.microsoft.com/?kbid=918824 says this behavior "by design".

On a side note, the message will show as Received in the Inbox at the delayed send time (say, 8:00am today). When you open the message, the Sent time will be the time the sender clicked the Send button (say, 5:00pm yesterday). This prevents a user from scheduling an email the night before saying, "I'm in the office this morning like you requested, but I'm going home now."


  1. Are there any server dependencies for this? I have clients (and can reproduce) not having mail sent if they close Outlook 2007 and they do not have Cached mode enabled.

  2. If a user running Outlook in Online Mode sends an email and immediately closes Outlook, Outlook will warn the user that an email is in the Outbox and has not been sent. Outlook will ask the user if he wants to send the email before shutting down Outlook.

  3. JEff, yes, this is the scenario, but my understanding is that the client should be able to close Outlook and still have it sent. They claim this was the behaviour in 2003, although I haven't confirmed.
    In summary, they must always have Outlook open to have the scheduled mail sent?


  4. Brad, if an Outlook 2003 user configures a message to "Do not deliver before" a certain date and time, the message will still appear in the user's Outbox, but Outlook does NOT need to be running when the message is sent.

  5. ... unless the user is in Cached Exchange Mode. Then Outlook must be running for the message to be sent at the appropriate time.

  6. There is one other dependency on this that I just ran into-- it's possible to have Outlook in Online mode but still have the a offline Address Book configured, and when you do deferred send with Outlook closed will not work. Go to Send/Receive and make sure "Download offline address book" is unchecked. For the record I also checked "Automatically Detect Connection State" when troubleshooting this issue.

  7. Anonymouse you mentioned that you turn off the 'Download offline address book" feature. Has anyone else seen that issue before with that feature?


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