Outlook Cannot Send This Item

Microsoft Outlook has a reasonably common, yet very generic error:

cannotNo Outlook, it was not helpful.

There are a bunch of reasons that can cause this error. Often, the ‘solution’ is to change the email from HTML to Rich Text or Plain Text, and move on. Or, copy/paste the entire email into a new email and move on. Neither of these are workarounds of course.

Dig a bit deeper on the web, and you’ll find some wackier reasons – the size of the logo in your signature for example. There was also a version of Exchange 2010 that caused the issue, but that was resolved.

I was running into this problem on a regular basis, and spent many hours trying to come up with a reason for the issue, and why only certain users had the issue, and on certain emails. I couldn’t reproduce on my own PC with the exact same emails, yet it was 100% reproducible on theirs. Also, if I removed the image from the user’s signature it fixed it – and it didn’t matter what image I put back in, it was always broken.

It wasn’t until I cried out for help on Twitter, and Christopher Kusek came to the rescue. After looking at a few other ideas, he pointed me towards hotfix KB3042197 with the lengthy title “ Graphics file attachment grows larger in the recipient’s email message after you change to a high DPI setting”

After reading this, I did some testing. Amazingly, the problem only occurred when the PC’s DPI setting was above 100%. Amazingly, when DPI is 125%, 150%, 200% etc, Word from inside Outlook resizes images in the HTML code based on your DPI setting. Some combination of HTML emails back and forth, and this resizing would cause the ‘Cannot send this item’ message.

Setting the DPI to 100% wasn’t enough either, as it would make the contents of the screen too small for some users. The registry setting mentioned on the KB article ‘DontUseScreenDpiOnOpen’ and setting the value to 1 (true) actually fixed it!

After some more testing, this single registry setting which you’d think would be on by default was rolled out, and the ‘Cannot send this item’ messages were no longer appearing. At least not for this particular problem!

TLDR: If Windows is set to > 100% DPI, the MS Word editor inside Outlook 2010 and Outlook 2013 will resize images by default and this can cause weird stuff to happen.

17 thoughts on “Outlook Cannot Send This Item

  1. Unfortunately, this issue is still occurring for us and we have invested hours (if not days) for a fix. A few of our end-users still receive the cannot send item or operation failed, when they attempt to reply or forward an email message. We have tried a repair of Outlook, recreating the Outlook profile, no signature when replying or forwarding emails, as well as switching from html to rich text.

    Any other ideas that I may have missed?

    Thank you!

  2. We also had this problem for a specific signature image. It turned out that the image carried an URL with country-specific characters, and this caused the issue. Changing the URL to be english-friendly solved our problem.

    1. Thanks for sharing – there’s a bunch of reasons this message can show up, so it’s great to know what the possible fixes are.

  3. Just to point one of the myriad of troubleshooting alternatives. I experiment today this problem and the cause was some graphics pasted from Excel (Office 2013), so I deleted the fancy graphics and I could save and send the message again. Of course, I closed and reopened Outlook and Excel, paste again the graphics and send the mail. This problem cause lot of headaches around the world as I can see.

    1. Thanks for sharing Mauricio – I don’t think anyone has made a full list of possibilities that caused this error, so I’m sure someone will have this same issue!

  4. This has happened a number of times for one particular employee of ours. We have swapped his machine with a freshly imaged one but it would seem to return, very frustrating!!…

    After another machine replacement today I finally discovered the issue (for our environment anyway), and confirmed I could reproduce it in Outlook 2010 on my own machine.

    In Outlook, File ==> Options ==> Mail, then second section from the bottom (Message Format): ensure that “Reduce message size by removing format information not necessary to display the message” is ENABLED.

    Seems he was turning off this setting each time after we gave him a new machine! I’ve had a quick look online but I don’t believe I have come across this as a fix, so hopefully it will help someone else :)

  5. If you also want to consider Downgrading to the previous build after an Update

    if you have outlook 2016 | outook 0365 client and exchange server on premise ( 2010 or 2016 ).
    if your outlook or Office automatically updates to version 1908 ( Build 11929.20254 Click-to-Run ) you will have the following issues .
    error when sending email with signatures : cannot send this item
    error when attaching file item : Operation failed
    Please consider downgrading to the previous version of office or outlook.
    Her we will be downgrading to August 13, 2019 Monthly Channel Version 1907 (Build 11901.20176) from August 26, 2019 version 1908 ( Build 11929.20254 Click-to-Run )
    Open command promt as administrator
    type this commands ;
    command 1 : cd C:\Program Files\Common Files\microsoft shared\ClickToRun\
    Command 2 : OfficeC2RClient.exe /update user updatetoversion=16.0.11901.20176

    Disable auto updates in outlook untill working fix is released or working updates are released.

    1. Thank You! This downgrade fixed the issue. It seems profile related, as I logged in as a different user and did not have the same issue. Still, for now this fixed it.

  6. I came across this issue yesterday. Windows 10, Outlook 2016 (16.0.11929.20234) 32-bit, on-premises Exchange 2010, no Cached Exchange Mode, with an image used in the signature. Removing the signature allowed emails to send, but with the signature included we saw “Cannot send this item”.

    Another confirmation here that turning on Cached Exchange Mode fixed it.

    Glad I spotted this thread!

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