I was looking at this a couple days ago. Follow the error message to the file ./classes/mailer.php
Mail is being sent out using this variable when sharing an article:
$to_combined = $to_name ? “$to_name <$to_address>” : $to_address;
The $to_name will be undefined when sending a message to: [email protected] …However, an address formatted like this: John Smith <[email protected]> should go out without an error.
I didn’t want to be bothered with adding a name so I updated the line: $to_name = $params[“to_name”] ?? “”;
The test email in preferences does not seem to care if the to name is missing.
I also had a look at mailer.php but an email like this John Smith <[email protected]> doesn’t work. The error ‘You must at leat provide one recipient email address’ is displayed.
It is not a required thing but maybe I just update the line like @jklm proposed