SMTP error 535 authentication failed in roundcube
SMTP Error (435): Authentication failed
If you face SMTP error 535 Authentication Failed while sending an email from round cube, then you can check the following things.
[root@server1 ~]# vi /usr/local/cpanel/base/3rdparty/roundcube/config/main.inc.php
and changed
$rcmail_config[‘smtp_user’] = ‘%u’;
to
$rcmail_config[‘smtp_user’] = ”;
That’s it 😀