If you are having issue in sending mails using roundcube as stated below.

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Once click the send email button, it appears the top window "sending message" and finally ends up with a timeout error (after some minutes).
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See the contents at /usr/local/cpanel/base/3rdparty/roundcube/config/main.inc.php and modify it accordingly in the below URL

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normally there is a series of lines which should read like this:

Code:

// SMTP username (if required) if you use %u as the username RoundCube
// will use the current username for login
$rcmail_config['smtp_user'] = '%u';

for now Roundcube seems to work properly if you change it to this:

Code:

// SMTP username (if required) if you use %u as the username RoundCube
// will use the current username for login
$rcmail_config['smtp_user'] = '';

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Problem with Roundcube (sending) SMTP error: Authentication failure: STARTTLS failed - Page 4 - cPanel Forums

If that seems to be ok, then you can try the script /scripts/autorepair net_smtp_fix

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[~]# /scripts/autorepair net_smtp_fix
Requesting script ... Done
Auto Repair is running...This autofixer will downgrade PHP's pear Net_SMTP if needed.
`/usr/local/cpanel/src/Net_SMTP/SMTP.php' -> `/usr/local/cpanel/base/3rdparty/roundcube/program/lib/Net/SMTP.php'

Downgrade complete
...Auto Repair is done
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