Campaign email says it will send, then won't send

Your software
My Mautic version is: 2.15.1
My PHP version is: 7.0.33
My Database type and version is: 5.7.31-cll-lve - MySQL Community Server - (GPL)

Your problem
My problem is: I have a campaign step to send an email. The email doesn’t send when the pending event time comes. It sets the time to an hour later. It keeps looping in this way, never sending or progressing in the campaign flow.

These errors are showing in the log:
There are no errors showing in the Mautic logs

Steps I have tried to fix the problem:
I have verified that all campaign and email CRONs are established:

The campaign looks like it is built correctly, here is a screenshot showing the steps. I’ve circled the step where my test contact is getting hung up. I’ve got a clip of the Contact’s screen showing that the email send is pending. When that time comes, nothing is sent, and the Upcoming Events list just updates the pending mail for an hour later. It repeats this, never sending the email:

I any email sending working at all?
What happens if you remove the batch limit?

Hi Joey, that was a good question. I actually added that yesterday because of someone who had a similar issue on a different forum post.

I actually just figure out what was going on. It was user error, unfortunately. My user didn’t understand that they needed to use a verified email (by Amazon SES) with the right domain as the sender address. They were using an address which wasn’t verified, resulting a bounces from the receiving server - three bounces and flagged.

After changing the email addresses on the mailing, they are now going out reliably.