Cannot Send This Item
This error message typically deals with how an outgoing email message has been formatted. If a user encounters this message, you’ll want to check the To:address first. This error can at times be generated because someone incorrectly formatted a destination email address incorrectly. Some versions of Outlook will state that the destination email address is unrecognized.
This error can also occur when there’s a problem within HTML-based email messages. Changing the outbound message’s format from HTML to plain text or rich text should resolve this.
It would also be worth testing an outgoing message when typing EVERY character of the recipient address as opposed to allowing Outlook to Auto-Fill the address. Occasionally a contact card can become corrupted and will incorrectly populate the information for the person or group you are sending to. If this fixes the problem, remove the contact and recreate it
