Thanks for getting back to me. When I run that command, I just get a 0 at the prompt, which i'm assuming means there was no error, which is consistent with that mail function in a php page. I commented out those two lines like you suggested. Here are the entries from mail.log that were made (i read the SO link you referenced and I tried multiple email addresses as well).
Jan 3 02:57:24 bitnami-lampstack-f27c sendmail: x032vOER002411: from=bitnami, size=100, class=0, nrcpts=1, msgid=201901030257.x032vOER002411@bitnami-lampstack-f27c.2nxmri0vlfuujai4x4yfypdfvc.bx.internal.c, relay=bitnami@localhost
Jan 3 02:57:24 bitnami-lampstack-f27c sm-mta: x032vOju002418: email@example.com, size=503, class=0, nrcpts=1, msgid=201901030257.x032vOER002411@bitnami-lampstack-f27c.2nxmri0vlfuujai4x4yfypdfvc.bx.internal.c, proto=ESMTP, daemon=MTA-v4, relay=localhost [127.0.0.1]
Jan 3 02:57:24 bitnami-lampstack-f27c sendmail: x032vOER002411: firstname.lastname@example.org, ctladdr=bitnami (1000/1000), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30100, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (x032vOju002418 Message accepted for delivery)
... as you can see it says message accepted for delivery, so I am at a total loss. When you refer to sendmail configuration, what are you referring to? Are you referring to /usr/sbin/sendmailconfig file?
Here is my support tool code if that helps lol: 248f3bec-7ffc-8b57-d30c-2a3fd20d9a77