Confirmation & Diagnostic Letters Not Sent (But SMTP Test Works)

Hi all,

I got a problem with sending confirmation letters to my subscribers.

1. Originally I could send confirmation letters to my subscribers — At least to my own Gmail. But later, all in a sudden, all my confirmation letters cannot reach my subscribers any more.

2. Nothing changed in Newsletter Main Configuration. It still works to send a test email to the test email address set up in Newsletter Main Configuration.

3. To test with Newsletter Diagnostic, it works to send an e-mail with WordPress, but it fails to “send few emails with Newsletter”, which error message is as following:

Newsletter TEXT test email NOT sent: try to change the sender data, remove the return path and the reply to settings.
Array
(
    [type] => 8
    [message] => Undefined property: NewsletterControls::$errors
    [file] => /var/www/wordpress/html/wp-content/plugins/newsletter/main/diagnostic.php
    [line] => 105
)
Newsletter HTML test email NOT sent: try to change the sender data, remove the return path and the reply to settings.
Newsletter both TEXT and HTML test email NOT sent: try to change the sender data, remove the return path and the reply to settings.

BTW, my Newsletter SMTP is with Yahoo service (smtp.mail.yahoo.com) with SSL.

Could anyone help me? Thanks a lot!

https://wordpress.org/plugins/newsletter/