I've gotten a few of these recently even though I'm able to email to the recipient from my primary email account. Here's an email with an example failed to send message:
Thanks for the heads up! We're looking into this and have identified an intermittent issue that's causing this problem. It's a 1 in 1000 case, but occasionally pops up as you've seen. We're working on a fix which should be in place in the next day or two.
In the meantime, if you see the issue, send the email a second time and it should work.
While I was reviewing your account, I noticed that your triggers going to an email of email@example.com (*'s for privacy since this is a public forum) are currently bouncing -- either the address is gone or its been reported as spam. Is that a correct address? If so I can look into getting it unblocked.
Just received another bounce. Can u check it?
Looks like that was firstname.lastname@example.org, yes? It looks like they pressed a "mark as spam" button on the "How can I help?" message from yesterday, which blocks us from sending to them. Sometimes people do that on accident, or don't realize that it will block further communication.
Can you contact them outside OwnerRez and make sure they're aware they will be receiving emails relevant to their booking from us? Let me know and I'll reach out to our email provider and get the block lifted.