Outlook Calendar Error "The attachment size exceeds the allowable limit", even when there is no attachment

Solution 1:

I have had exactly the same problem for the past week or so. I came across this post which has helped me to resolve the issue.

The problem seems to be that there is a limit when working in 'cached exchange mode'. I did the following in Outlook 2007:

  1. Go to 'Tools > Account Settings...'
  2. On the 'E-mail' tab click on your account
  3. Click 'Change...'
  4. Uncheck 'Use Cached Exchange Mode'
  5. Click 'Next >' - you will see a dialogue box advising you that you will need to restart outlook; click 'OK'
  6. Click 'Finish'
  7. Click 'Close'
  8. Close and restart Outlook
  9. You should now be able to delete the appointment that was giving you the error

If you need cached exchange mode to be enabled (for example, if you are using Windows Desktop Search on your PC), go through this process again but this time check the 'Use Cached Exchange Mode' box in step 4.