Frequently Asked Question
The QuickBooks desktop program integrates directly with the Microsoft Outlook application on the machine where QuickBooks Desktop is installed. Since QuickBooks is a 32 bit program, it appears to only be compatible with the 32 bit version of Microsoft Office.
In addition to requiring 32 bit Office be installed on the same machine as Quickbooks Desktop, there are a number of additional configuration issues that could cause sending emails from Quickbooks to fail. See the following article for detailed configurations that can be modified in order to correct the issue.