Prevent sending messages that are too large

Sometimes I add attachments which are too large to send and the message will hang in my Outbox.

I know my ISP has a limit of 20MB but I sometimes get too excited with adding large pictures or other stuff.

Is there any way I can work around this so that I don't get any Send/Receive errors and have to pry them out of the Outbox?

Message Size buttonYou can create a rule that checks if the message is larger than 20480KB and if it is to postpone the message by 120 minutes.

This will allow you enough time to cancel the message.

Step-by-step instructions

Manage Rules & Alerts buttonTo create a rule to automatically prevent larger email from sending follow the instructions below.

  1. Create a new rule:
    • Outlook 2007
      Tools-> Rules and Alerts…
    • Outlook 2010, Outlook 2013 and Outlook 2016
      File-> section: Info-> button: Manage Rules & Alerts
  2. Press the New Rule… button and start with a blank rule:
    • Apply rule on messages I send.
  3. Press Next.
  4. Select: with a size in a specific range.
  5. In the section at the bottom, click on: in a specific range.
  6. Set the following sizes:
    • At least: 20480
    • At most: 999999
  7. Press OK to close the Message Size dialog.
  8. Press Next.
  9. Select: defer delivery by a number of minutes.
  10. In the section at the bottom, click on: a number of.
  11. Set the value to: 120.
  12. Click OK to close the Deferred Delivery dialog.
  13. Press Next,  then Next again and then on Finish to complete creating the rule.

The whole message rule now should be;

  • Apply this rule after I send the message
  • with a size at least 20480 and at most 999999 kilobytes
  • defer delivery by 120 minutes

Note: 1MB (megabyte) is 1024KB (kilobyte), so in our example 20MB is 20480 kilobyte

Setting the attachment size limit in Outlook 2010, Outlook 2013 and Outlook 2016

Registry Editor buttonIn Outlook 2010 and later, there is another way to do this and that is by changing a Registry key. For more information about this solution see; Increase the maximum attachment size limit

Note: If you have message hangs in the Outbox see; Message stuck in Outbox

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