When I run Outlook in Cached Exchange Mode, I have nothing in my Outbox.When I run Outlook without Cached Exchange Mode, I have 2 messages in my Outbox. Both of these messages are old. I'm sure that they had been sent, delivered, and acknowledged by the recipients.If I look at my Outbox from PFDAVAdmin, I see -3- messages in my Outbox: the 2 messages that I see from Outlook, plus something called Send To.eml.Our IT director, when running Outlook in Cached Exchange Mode, has nothing in his Outbox.When he runs Outlook without Cached Exchange Mode, he has a few *hundred* messages in his Outbox. I don't think he can say with certainty that every message has been sent, but he's fairly certain about most of them.If I look at his Outbox, he has only -1- message: that strange "Send To.eml" message that I also see in my Outbox.Other people also have items in their Outboxes, items which they're fairly certain have already been sent. Some have a few; some have hundreds.Other people on this forum have reported problems with e-mail getting "stuck" in the Outbox, and the "solutions" have been to delete the messages (while out of Cached mode), or to move the mailbox to another mailbox database.Is there any available information on why this happens? For us, it seems to be just a nuisance, but "delete them and don't worry about it" is a hard answer to give to our user community.

Compare what you're seeing in Outlook (without cached mode) to what you see in OWA. They should be 100% the same. I would suggest deleting your OST file and letting Outlook rebuild it. Then see whether this problem recurs.Lanwench [MVP - Exchange] ** Do not fold, spindle or mutilate. Fill in the box completely and erase any stray marks. Use only a #2 pencil.

Hi,I recommend you to use MFCmapi.exe to check the messges in outbox,if it does exist there,then you can delete there and then monitor the issue for some time.http://www.microsoft.com/downloads/details.aspx?FamilyID=55FDFFD7-1878-4637-9808-1E21ABB3AE37&displaylang=enRegards,Xiu

There was a bug in Outlook that caused this. What version and service pack level is Outlook at?Active Directory, 4th Edition - www.briandesmond.com/ad4/

Please refer to MS KB 948984, An Outlook 2007 e-mail message remains in the Outbox after you have moved it to a personalfolder (http://support.microsoft.com/kb/948984). You need to apply the registry in each user profile and in client side, i.e. the user is logged in. It works well in my case.MS KB 948984 1. Exit Outlook 2007. 2. Start Registry Editor. 3. Locate and then right-click the following registry subkey: HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Cached Mode 4. On the Edit menu, point to New, and then click DWORD Value. 5. Type SendOne, and then press ENTER. 6. Right-click SendOne, and then click Modify. 7. In the Value data box, type 0, and then click OK. 8. On the File menu, click Exit to exit Registry Editor.