SSL operation failed with code 1

Hi guys,
test email log says: string(43) “SMTP Error: Could not connect to SMTP host.” and I got this error on my apache log:

PHP Warning: stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages:\nerror:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed in /var/www/vhosts/xxxxxxxxxxxx.it/httpdocs/wp-includes/class-smtp.php on line 368\n', referer: https://xxxxxxxxxxxx.it/xxxxxxxxxxxx/wp-admin/options-general.php?page=wp-mail-smtp%2Fwp_mail_smtp.php

These are my settings (doublechecked and perfectly working with my mail client):
from email: [email protected]
SMTP host: mail.xxxxxxxxxxxx.it
SMTP Port: 25
“No encryption” selected
“Yes: Use SMTP authentication” selected, with theese settings: username [email protected] and password xxxxxxxxxxxx

I’ve googled a while and I’ve found this suggestion, wich does NOT solve my problem:

add_filter('wp_mail_smtp_custom_options','my_wp_mail_smtp_custom_options');
function my_wp_mail_smtp_custom_options($phpmailer) {
	$phpmailer->SMTPOptions = array(
		'ssl' => array(
			'verify_peer' => false,
			'verify_peer_name' => false,
			'allow_self_signed' => true
		)
	);
	return $phpmailer;
}

My server runs PHP 7.1.6 and mounts a COMODO SSL Certificate.
Any idea on what to investigate?

Thanks in advance,
Christian

–update–
I found that by changing “SMTPAutoTLS = true” to “SMTPAutoTLS = false” into class-phpmailer.php solves the problem, but I guess it is not the correct way to proceed. Any advice?

• This topic was modified 7 years, 3 months ago by Christian Gatti.