is there a way to add insurance options for shipping for AbanteCart for the latest USPS module by WHY2 (version 1.3.3)?

I have recently rolled out AbanteCart 1.3.3 on my new store.

Testing the store, the paypal and cards are processed but no emails are being sent of new orders to myself or to end customers.

I have verified the email templates are all in my language (English).

I try to update an order and notify the customer but nothing.  i have checked spam and junk mail folders as well.

I have configured it to use the 'Mail' option as recommended

Alert Email is enabled

I have seen the below errors in the Error log:
2022-08-14 6:59:59 - AMail. transport: Symfony\Component\Mailer\Transport\SendmailTransport: Unable to write bytes on the wire.

I have also verified in my PHP my sendmail path is set to:
/usr/sbin/sendmail -t -i -f myusername@mydomainname.com

Any help would be appreciated.

I even get the above error when I try to use the 'Contact Us' page.  The page after submission states 'Your enquiry has been successfully sent to the store owner!' but no email ever comes through to my email.