SMTP host error

I’ve just installed phpList and I’m experiencig the following problem. With this config

define(‘PHPMAILERHOST’, ‘mail.HOST’);
define(‘PHPMAILERPORT’,587);
define(‘PHPMAILER_SMTP_DEBUG’, 1);

$phpmailer_smtpuser = ‘user’;
$phpmailer_smtppassword = ‘pass’;
$phpmailer_smtpport = ‘587’;

I’m getting the following error when sending the test message

CLIENT -> SERVER: EHLO heuristica.barcelona
CLIENT -> SERVER: STARTTLS
SMTP Error: Could not connect to SMTP host.
CLIENT -> SERVER: QUIT
SMTP ERROR: QUIT command failed:
SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

phpList is saying that it cannot connect to the smtp server.

you will need to try variations of settings until you find one that works. One trick is to setup an email account using outlook or thunderbird, and use the settings that work in the email client as a starting point for the settings used in phpList.

I’m having this error with the same config I have in thunderbird.

However, when sending the first mail from thunderbird I need to confirm a security exception. Perhaps this is the problem and it is in the server side.

Yes, not a good sign