I'm also having this problem trying to send an invoice to my client from my Macbook Pro. It just started recently. I can't be sure this is the cause, but Microsoft just recently forced my Outlook to the "new version". I was running the "legacy" version before that.
I've looked thru all the Quickbook settings, but can't find any way to select (or reselect) Outlook as my email program.
I also rebooted my system just in case.
Still getting "QuickBooks is having problems communicating with your email program."
Please help
