stammnetworks

Error message of your plug in:

Array
(
[error] => FAIL – check details below

[error-info] => Array
(
[last-error] => Array
(
[type] => 8
[message] => Constant WP_DEBUG_DISPLAY already defined
[file] => /var/www/html/Kunde1112/wordpress/wp-config.php
[line] => 101
)

[phpmailer] => SMTP Error: Could not authenticate.
)

[debug] =>

Hello Oliver,

I am pretty sure that credentials will be working correctly. I have typed and pasted the credentials for several times. Nevertheless the SMTP Mailer Plug-in should be a reference to yours. I have tested both and came to the point that both will have similar behavior while using the correct credentials. The SASL Auth will not be performed correctly. This is a bug regarding PHP and can be fixed simply disabling the cert validation. (My perspective) can you please provide PHP version of the testing environment? How can I disable cert validation within your phpmail class?

Regards
Carsten