Cant close, *not send*, Outlook emails with large attachments: "Attachement exceeds allowable limit"

Hi guys,

I have a strange one that I cant find an answer for anywhere.

We have outgoing email size restrictions of 5MB and no incoming email size restrictions.

The Outlook client is fully patched with SP3. We are running Exchange 2010 which is hosting multiple email domains and has 3 mailbox databases. I have recently been forced to apply the 5MB send limits to our mailbox database as my users were abusing the 30MB global limits which are a lot higher than they were used to. I cannot confirm if the issue I am posting about here is a symptom of applying lower send limits on our mailbox database but I am mentioning it as it might assist in isolating this issue.

If an Outlook 2007 client opens an email that has attachments that are larger than we allow to send, I cant close the email after opening it. And it goes without saying I cant forward it unmodified.

Also, if I try to forward the email once I have deleted the attachments which exceed our allowable limits, it still gives a warning, "attachments exceed allowable limit", with no attachments at all.

However if I reply to the email (no attachments by default) rather than forward its able to be sent on.

I have seen this blog post on the issue but it doesn't help as the values are already set. many times larger than our maximum send limits http://tsoorad.blogspot.com.au/2008/01/outlook-attachment-size-error.html

Has anyone encountered this before and knows how to correct it?