Last reviewed on September 16, 2014   —  68 Comments

If you view 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, BCM (Business Contact Manager), and more recently, the iCloud add-in installed by iTunes. A list of other add-ins known to cause this behavior is listed below.

Antivirus/security software is often the culprit as it is looking for viruses and spam. Disable add-ins installed by the security software to solve.

iCloud is quickly passing Anti-virus add-ins as a frequent cause. It’s installed by iTunes and if you are not using syncing with an Apple device using iCloud, you can disable it. Apple also installs two additional add-ins (Change Notifier and Outlook Add-in) that are not needed if you don’t sync with an Apple device. If you are using iCloud, avoid viewing the Outbox and switch to another folder before re-sending messages you opened from the Outbox. See Outlook and iCloud 2: What you need to know for the more information.

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:

If using Outlook 2003: Look in Tools, Options, Other, Advanced, Com add-ins. Disable the add-ins and re-enable them one at a time and test.
Outlook 2007: Look in Tools, Trust Center, Add-ins.
Outlook 2010: File tab, Options, Add-ins.
Outlook 2013: File tab, Options, Add-ins.

Click the Go button to disable com addinsClick Go button at the bottom of the dialog to disable add-ins. Select Disabled Add-ins from the dropdown menu to re-enable add-ins.

Since BCM and possibly other add-ins are not listed in the COM add-in list, check



If using Windows 7 or Vista 64-bit, addins are in the following HKEY_LOCAL _MACHINE key.

HKEY_LOCAL _MACHINE\Software\WOW6432Node\Microsoft\Office\Outlook\AddIns

When you use a 64-bit OS, some add-ins are listed under both HKEY_LOCAL_MACHINE locations. Check the HKEY_LOCAL _MACHINE\Software\WOW6432Node path first but if its listed in both locations, you may need to set LoadBehavior to 0 in both locations.

Export the keys then change the LoadBehavior value to 0 to disconnect an add-in. Restart Outlook and test.

If you need a quick tutorial on editing the registry, see How to Edit the Registry

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 or an update – newer versions of some of these applications will not cause problems. If the problem is caused by the newest version, disable or uninstall the addin.

  • iCloud addin. used to sync with Apple devices. Disable if you are not using it to sync.
  • AVG (Free version tested) – disable avgoutlook.Addin. Set LoadBehavior 0. (From “Thunderbird“: you need to disable two keys for avgoutlook.Addin when using 64-bit Windows 7)
  • Bitdefender Internet Security
  • Symantec Endpoint Protection
  • Social Connector with Outlook 2007

If you are using one of these older applications, look for a newer version:

  • iTunes Outlook Addin
  • 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
  • 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 – Upgrade to the newest version of Xobni.
  • Auto-Mate
  • RingCentral Add-in
  • DesktopSMS.Addin
  • ABBYY PDF 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.


  1. B Bradby says

    Thanks a million. I found an add-on that had been inserted into my Outlook 2007 when I had downloaded a free trial version of a pdf-word converter programme a few weeks ago. Removing that seems to have solved the problem.

  2. Shamsul says

    I can't send my email, goes to outbox, massage comes smtp or password not correct, could you help me please. Thankyou

  3. Linda says

    The information given above is too technical for me. When I follow the instructions to go to Tools, none of what it says I will find, can I find. The websites do not help because I do not understand. I STILL can not get my email to "send" and therefore get it out of outlook. Also, a network password box keeps poping up--I do not know why, or how to get rid of it. It interferes with everything !!!!

    • Diane Poremsky says

      What version of Outlook do you use? This can affect the menus you see.
      Re: the password dialog - Who is your email account with? Do you read your email on a smart phone too? We know of issues with BT/Yahoo and AT&T/Yahoo accounts - see Never-ending password dialog.

  4. Matt says

    I had the same issue and found out that the add-in called NetPhone Addin caused my issue. This Add-in was found in my SysWOW64 directory and I think it related to Toshiba Call Manager.

  5. Gary says

    Thanks. You can add to the list of culprits the Evernote COM addin. I disabled it and the problem was resolved on Outlook 2003.

  6. Lorrie says

    Thank you! I disabled a couple of MS Exchange ad-ins out of Outlook 2007 (I don't need to use Exchange) and also the iTunes and iCloud add-ins -- and it worked! It is sending.

    Not sure about adding the Apple ones back in yet. Just glad I got it to send again out of my Outbox and not keep the message in there, looking like a 'read' email. No errors, nothing. Not a problem with the server, test messages were sending fine.

    So frustrating.Disabling these add-ins worked for me, thanks again!

  7. steve fryatt says

    I just had this problem and was nervous about editing the registry so uninstalled software starting with iTunes but still had the problem. I finally solved it by removing Apple's iCloud executable that runs continuously in background (installed via iCloudSetup.exe) I use Outlook2003.

    • Diane Poremsky says

      Thanks for sharing which program caused it - icloud doesn't work with Outlook 2003 so its pointless to have it installed. If you don't sync an iDevice with Outlook, you don't need itunes addin either.

  8. John Passarella says

    I just had the same problem. Date: None in outbox if I viewed the folder with a message in there that hadn't been sent yet. Tried trial and error. Was hoping it was Norton Anti Spam since that takes forever to load anyway, but it turned out to be iCloud add-in. Tried iTunes first. Same issue. Disabled iCloud and it works again.

  9. Luis says

    My problem: some messages would be marked read, in Outlook 2007, and would not send. I uninstalled iCloud and problem solved!

  10. heathclifff says

    I've had this problem for weeks, and it was driving me nuts. I finally decided to figure it out. You gave me the answer. I disabled iCloud add-in, and my mail is now sending. What is iCloud add-in for?

    • Diane Poremsky says

      The iCloud addin is installed by iTunes and used to sync Outlook's calendar and contacts with an iPhone or ipad using Apple "icloud" network. If you don't sync with an Apple device, you don't need it enabled.

  11. brishel001 says

    Excellent information, in my case the problem was the "Apple.DAV.Addin" addin. I changed the load behavior from 3 to 0, restarted outlook and this resolved the issue. Thank you!

  12. Lynda says

    Thanks a million Diane - you're a gem! Problem solved - I disabled the icloud and one note add-ins, plus in the process got rid of the social networking thingy that was driving me nuts! Keep up the good work!

  13. Thomas says

    Changed the Load Behaviour value for my Anti Virius program and now emails don't open in Outbox when it's opened. Thank you for this great fix. Program to add to the list you already have is Bitdefender Internet Security 2013

  14. Andrea says

    Thanks for the information! I "unchecked" the iCloud add-in that downloaded when iTunes updated on my computer and it worked like a charm! I NEVER would have figured that out without this information. THANKS!!!

  15. Sander says

    thank you !!!

    i Had this problem and i do want emails to go through my outbox before being sent every 20 minutes. it seems that the icloud addin was causing the problem because problem over after disabling the addin.

    was very annoying so thanks for the tips.

  16. MichaelDuturbure says

    I have disabled all the addins....and still I am having this problem. I am only having it on one profile of my outlook (my main one) and it started a few days back.

    • Diane Poremsky says

      What type of email account do you use?
      Do they send in Safe mode?
      Do they send if you don't look in the outbox?

      To open Outlook in Safe mode: Close Outlook then hold Ctrl as you click on the Outlook icon. You'll get a message asking if you want to start in Safe mode. Click Ok.

  17. SDK says

    Thank for writing this article! I disabled the 'iCloud' add-in and the delay delivery feature now works. Many thanks!

    Stupid Apple!

  18. Surachai says

    Do you have any solution to fix this problem without disable iCloud add-in?

    Our user need to use iCloud add-in to sync with his apple devices?

    • Diane Poremsky says

      Do the messages send if you don't view the Outbox? If so... you can keep the icloud as long as you stop looking in the outbox. :)

      If the problem is that mail just won't send and you are not looking in the outbox, one person said they reinstalled icloud and it worked correctly (messages did not get stuck).

  19. Eric says

    Hi, I solved the same problem this way (I had 100 email waiting to be send while working on a plane...) : I select one, then I click FORWARD (the recipient name populate automatic), then click SEND. I delete the file that stays in my Outbox.



  20. Alan Mayo says

    Thanks, so much, installed Icloud the other day and later realised that I was getting erratic behaviour when sendig email from my outllook account. Any email that I saved before sending, and any replies I was sendijng remained in the outbox with the draft icon. Disabling the icloud outllok add in has dealt with that. But do I need that add in in order for Outlook to synch my calendar with icloud?

    • Diane Poremsky says

      Yes, you need it if you want to sync with outlook. Usually... there isn't a problem with the icloud as long as you don't look in the outbox. I'll test it and see if i can repro this issue. Which version of Outlook do you use?

  21. wschloss says

    Hi, this info looks very helpful but a bit of clarification if you don't mind. When I look at the Outbox I don't open the individual messages, and my preview window is not turned on (in fact it can't be turned on for Outbox, unlike other folders the option is not available), and the messages are still clearly marked as unread. If I do or do not then go to a different folder, and hit send, the messages won't go. In all other instances it works perfectly. (Outlook 2010, Win 7, lots resources). I am not on Exchange but do have iCloud and AVG, and don't wish to disable either.

  22. wschloss says

    Sorry, PS, the workarounds above DO work and if that's what I have to do for a while, then so be it. But it is pretty annoying, and I hope for a "permanent fix." Thanks for your help!

    • Diane Poremsky says

      Do you know which addin is causing the messages to be marked as read?

      Oh, never mind - it's either AVG or icloud.

  23. Jonathan says

    I am trying to disable an add in in outlook ( teamviewer meeting add in) which I suspect might be a problem , but I get a message saying that only an administrator can disable the add in. I am the administrator and only user on my laptop. How do I solve this?

    • Diane Poremsky says

      Close Outlook, right click on the outlook shortcut you use to start it and choose Run as admin. If you don't see run as admin, hold shift as you right click. should be able to disable it now.

  24. C Malmgren says

    Thank you for the help. I-cloud add-in was the source of my problem. The fix for me was to remove the i-cloud feature from the "control panel> programs and features" since I wasn't using it anyway.

  25. lisaskil says

    You are a life saver... This bug was absolutely driving me nuts and it seemed to be fairly recently introduced. I am glad I am not going crazy and this really was an issue!

  26. 409industries says

    Excellent post. I had been banging my head against the wall wondering why one of our execs could not send email via their Exchange account in Outlook 2010. Only on this one particular computer (a home PC) turns out that the iCloud add-in was the culprit. Once disabled, email was sending again!

  27. TOM MARCH says

    Finally fixed! It was the Add-in btmoffice.Connect. I set the behavior value to 0 in the registry and Office emails send again. Thanks.

  28. Larry says

    Hurray! This has been bugging me for over a year now. Turns out iCloud was the problem. Re-opening the messaging, changing the viewed folder, then re-sending the message is the workaround that works for me.

  29. Nizam says

    I am using Out Look Express 07 for e-mails. I have settled an accout and it was correctly, but now a days when I am trying to send any files it is not moving from the out box while the reciever it is recieving. Can anybody help me on this issue?

    • Diane Poremsky says

      When mail isn't moved to the sent folder its usually the antivirus filter. What do you use for antivirus?

  30. Shabana Ahmed says

    In our case the issue is happening with our custom Outlook Add In, How do we fix the Add In code to not mark the mails as read?

    • Diane Poremsky says

      I checked with the outlook dev experts and one recommended turning it off when switching to the outbox (then turning it back on). I'm not sure its the best option... and if you use redemption, maybe you can resubmit the message when switching out of the folder.

      Public Sub TurnOff ()
      On Error Resume Next
      Dim Addins As COMAddIns
      Dim Addin As COMAddIn

      Set Addins = Application.COMAddIns
      Set Addin = Addins.Item("AddinName.Connect")
      Addin.Connect = False
      End Sub

      For "AddinName.Connect" see the correct class identifier in the registry.

    • Diane Poremsky says

      This from another dev expert -

      A properly written addin won’t do anything to messages in Outbox. If you do some accesses on the message using Redemption it doesn’t cancel the submission to the transport. Doing almost anything with the item using the OOM will cancel the submission. Calling Send() on the item will re-submit it. You can check Submitted (Boolean) in either RDO or OOM to see if the item is submitted.

  31. Luismi says

    Many Thanks! It happens to me with Add-In "SugarCRM", just for you to add to your list. Once I disabled it, it worked again. But I need it, so I have to enable it again, and just avoid looking in the Outbox...

  32. Carl says

    I set the icloud to zero in the add-ins. no change. I have this intermittent issue where sometimes my outlook 2007 on windows 7 will not send the message in the outbox. Sometimes it is when I am wifi on Comcast and it is not comcastic. Other times it is on my own isp, The current one is a recall the message, message that will not send, nor can I open it in the outbox.

    My accounts are an using MAPI, as POP didn't send either and was worse. My other two are POP/SMTP accounts. My outlook connector is connected. This recall is on the account message.

    I don't use any antivirus other than Windows Essentials. Is this just MIcrosofts way of getting me to buy Outlook 2013?

  33. oorsini says

    Thanks this fixed my problem of email getting stuck in outbox!
    I disabled the Norton AntiSpam Outlook plugin (this was likely problem) and Winzip ZipSend.

  34. Eric says

    Ran into this with Cisco's Click to Call. I was able to bypass the issue without disabling the add-in by removing the add-in's button from the Outlook ribbon. The other functionality of the add-in still works.

  35. Tom says

    This totally helped. I have my Outlook configured to keep message in Outbox until I hit "Send-Receive". If I edit it in the Outbox the "Date" gets set to "None". When I am ready to send it for sure, I just have to click "Send" on the message again, which changes the "Date" to "Today". However, starting yesterday hat wouldn't work - the "Date" would still be "None" even if I hit "Send". By following the instruction above to "navigate to another folder before hitting "Send" it resolved the problem.

  36. James says

    Thanks to Diane's note about iCloud causing the problem, and Larry's (June 2013 commenting) workaround.

    Since I have to use iCloud (for now) as well as Outlook 2010, and I always check the outbox before hitting send, and since making registry changes worries me, that will have to do!

  37. Mark says

    Brilliant - thank you. I opened the email, chose another folder, then hit send, and waited for progress on all accounts to complete. The email was sent. I will get back and figure out which plugin is causing this pesky little problem - thanks again.

  38. Cristina says

    I had this problem. Such a strange bug, thanks for explaining how the messages are marked as "read" by some Add-ins. This is great.

  39. Mike says

    This remains a maddening problem in the summer of 2015! My solution (a quick and easy work around) is to take anything sitting in the Outbox that won't send (if it's been "read" or is listed in the "Date: None" column) and drag it into the Drafts folder. I then open it in Drafts, click send, and it goes out immediately. (This is much better than when I was creating new emails...!)

    • wschloss wschloss says

      I too still have this most annoying problem, and none of the above fixes ever helped. Office 2010, Win 7 64. Anyone know if it's fixed in Office/Outlook 2013 or 2016, even without add-ins? If not I don't want to pay for it? Thanks.

    • Diane PoremskyDiane Poremsky says

      it's not fixed - the same addins that cause it in the older versions cause it in outlook 2013 and 2016. If you don't have addins or utilities reading the outbox, the messages shouldn't be affected.

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