Mail getting stuck in Outbox

Question

I am using Outlook 2007 and exchange server.  When send emails they oftentimes get stuck in the Outbox with a sent date of "None".  If I restart outlook and try resending the messages, they will oftentimes go out.  I am having to restart outlook 5 times a day right now.  Any ideas what would cause emails going out through exchange server to just "get stuck"?  Sometimes when I sent the emails and I watch the Outbox folder, the messages will appear in the outbox with a "sent" date, then after a second or so that "Sent" date will just change to "none" and the email just won't go out.  Any advice on how to troubleshoot or fix? 
One other note...some messages just NEVER go out 9regardless of how many times I hit restart outlook and hit send) and I need to rewrite them by creating a new message and sending and that new message.
NOTE: this appears to happen when I'm in a state where I am "Connected to Microsoft Exchange".

Answer 1

 DontPanicZ wrote:
Hello,
I found a solution that worked for me.
See:  http://www.slipstick.com/problems/outbox.htm
I followed the suggestions in the article and found that I had an add-in (that I did not need).  When I disabled the add-in, my problem was solved.
Text of article follows:
After viewing the Outbox, the messages in it won't send.
If you click on the Outbox while messages are waiting to be sent, the messages are marked as read and won't send.
This is caused by a Net framework add-in you have installed that 'reads' Outlook items, including the Send to OneNote from Outlook PowerToy add-in and BCM (Business Contact Manager). A list of other add-ins known to cause this behavior is listed below.
To send the affected messages, you'll need to open the message, then switch to a different folder before clicking Send on the message. Do not go open the Outbox until after the messages are sent.
To identify the add-in that results in this behavior:
Look in Tools, Options, Other, Advanced, Com add-ins. Disable the add-ins and re-enable them one at a time and test.
Since BCM and possibly other add-ins are not listed in the COM add-in list, check
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\Outlook\Addins
HKEY_CURRENT_USER\Software\Microsoft\Office\Outlook\Addins
Export the keys then change the LoadBehavior value to 0 to disconnect an add-in. Restart Outlook and test.
Applications responsible
The following is a list of some of the applications which are reported to cause message to be marked as read. If you use these or any other add-ins, check for a newer version - newer versions of some of these applications will not cause problems. 
ICQExpress (COMAddin), installed as part of ICQ
Business Contact Manager (BCM)
Send to OneNote from Outlook PowerToy
Outlock
Outlook Backup Add-in
Sierra Wireless Outlook Integration - disable in the registry. It's listed at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\Outlook\Addins\SwiOutlookInt.Addin
ONFOLIO
Timeslips add-in
Attensa for Outlook. Check for upgrade: newer versions not affected.
Cisco Meetingplace plug-in
MindJet Mind Manager 6. Disable the add-in in the registry - the key is Mindjet.Mm6OutlookLinker.AddIn.2
Google desktop "search your own computer", specifically because it searches the mail
ScanSoft PDF Converter Outlook Addin
Norton AntiSpam Outlook Plugin
Norton Internet Security
AIM Sync
LinkedIn Outlook Toolbar
Salesforce
Upshot Outlook integration
MS CRM 3.0 Outlook Add-in
Xobni
Auto-Mate
RingCentral Add-in
DesktopSMS.Addin
More Information
If your mail won't send and it's not the problem described above, other possible causes are:
Authentication problems: Are you logging on to the mail server correctly?
No default mail account. If you can reply to messages but not send new message, check the account settings and make sure one is set as default. When you use a configuration script created by your mail provider or import accounts, an account is not always set as default.
See Email Won't Send - Common Causes for more information.