If you’re finding that there is no “Outlook” option in Quickbooks’ preferences for “Send Forms” but, instead, only Web mail and Quickbooks email, the following will put it back:
Edit C:\Windows\WIN.INI and insert the following lines:
[MAIL]
MAPI=1
MAPIX=1
After saving this modified file, start Quickbooks and you will see the “Outlook” option has returned.