I thought someone posted that the issue might be fixed in a future update.  If you have the most recent update and are still having problems, evidently the future has not yet arrived.

I'm pretty sure the issue is not "processor" but the Email Client program being 64-bit vs 32-bit. And I seem to remember a topic stating that the next release for Jan 20 will restore the option to select if you are using 32-bit or 64-bit email client (such as Outlook or Thunderbird).

I found it:

https://proconnect.intuit.com/community/proseries-tax-idea-exchange/please-give-make-the-use-of-64-b...