Sending Bouncing with SMTP Error: The following recipients failed

I have added some subscribers to test the bounce rules, but I’m not able to send them emails as the processqueue returns:
“Error sending email to SMTP Error: The following recipients failed: sorry, user unknown”

What could I do, that PHPList automatically adds these email addresses to be blacklisted?

Thanks for any help.

Sounds like your SMTP server received that error from the remote mail server. Sure that the addresses are correct?

The addresses are fake, as I’m testing configuration of my PHPList installation.
I guess I need to enable some kind of email validation to see what happens if someone enters fake email addresses.
Will post the final settings here.

You can use this plugin to ban disposable email addresses:

There’s no good way to strictly validate that email addresses are valid as far as I’m aware.

Thanks for the suggestion!

Right now I haven’t found any automatic solution for dealing with failed sending emails and stopping the retry automatically. As I read PHPList maybe able to handle it, if not I will receive the processing log by email and could stop the process manually.