Could not open socket

Hello people,

I configured SMTP as per post https://support.themecatcher.net/quform-wordpress-v2/guides/email/using-the-post-smtp-plugin-to-send-emails-via-smtp, but it showed me the error “Could not open socket”.
See the test diagnosis below:

Mailer: postsmtp
HostName: mysite.com
cURL Version: 7.62.0
OpenSSL Version: OpenSSL/1.0.2k
OS: Linux us-imm-web355.main-hosting.eu 3.10.0-962.3.2.lve1.5.31.el7.x86_64 #1 SMP Mon Feb 17 04:30:31 EST 2020 x86_64
PHP: Linux 7.2.29 C
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=Yes, allow_url_fopen=Yes, mcrypt=No, zlib_encode=Yes
WordPress: 5.4.2 pt_BR UTF-8
WordPress Theme: XStore Child
WordPress Plugins: Akismet Anti-Spam, All In One WP Security, Contact Form 7, Elementor, XStore Core, Facebook for WooCommerce, Jetpack by WordPress.com, WPBakery Page Builder, Google Ads for WooCommerce, Loco Translate, Mailchimp for WooCommerce, MC4WP: Mailchimp for WordPress, Massive Addons for WPBakery Page Builder, Post SMTP, Quform, Slider Revolution, WooCommerce Infinite Scroll and Ajax Pagination, Smart Product Viewer, Subscriptio, W3 Total Cache, WooCommerce Dynamic Pricing & Discounts, WooCommerce PDF Invoice, WooCommerce Services, WooCommerce, WZone - WooCommerce Amazon Affiliates, GMAPS for WPBakery Page Builder, YITH WooCommerce Wishlist
WordPress wp_mail Owner: /home/u486489869/domains/mysite.com/public_html/wp-content/plugins/post-smtp/Postman/PostmanWpMailBinder.php
WordPress wp_mail Filter(s): wp_staticize_emoji_for_email, PostsmtpMailer->get_mail_args
WordPress phpmailer_init Action(s): wpcf7_phpmailer_init, WC_Email_New_Order->handle_multipart, WC_Email_Cancelled_Order->handle_multipart, WC_Email_Failed_Order->handle_multipart, WC_Email_Customer_On_Hold_Order->handle_multipart, WC_Email_Customer_Processing_Order->handle_multipart, WC_Email_Customer_Completed_Order->handle_multipart, WC_Email_Customer_Refunded_Order->handle_multipart, WC_Email_Customer_Invoice->handle_multipart, WC_Email_Customer_Note->handle_multipart, WC_Email_Customer_Reset_Password->handle_multipart, WC_Email_Customer_New_Account->handle_multipart, RP_SUB_Email_Customer_New_Subscription->handle_multipart, RP_SUB_Email_Customer_Activated_Subscription->handle_multipart, RP_SUB_Email_Customer_Subscription_Trial_Started->handle_multipart, RP_SUB_Email_Customer_Paused_Subscription->handle_multipart, RP_SUB_Email_Customer_Reactivated_Subscription->handle_multipart, RP_SUB_Email_Customer_Resumed_Subscription->handle_multipart, RP_SUB_Email_Customer_Overdue_Subscription->handle_multipart, RP_SUB_Email_Customer_Suspended_Subscription->handle_multipart, RP_SUB_Email_Customer_Subscription_Set_To_Cancel->handle_multipart, RP_SUB_Email_Customer_Cancelled_Subscription->handle_multipart, RP_SUB_Email_Customer_Expired_Subscription->handle_multipart, RP_SUB_Email_Customer_New_Renewal_Order->handle_multipart, RP_SUB_Email_Customer_Processing_Renewal_Order->handle_multipart, RP_SUB_Email_Customer_Completed_Renewal_Order->handle_multipart, RP_SUB_Email_Customer_Subscription_Payment_Reminder->handle_multipart, RP_SUB_Email_Customer_Subscription_Payment_Failed->handle_multipart, RP_SUB_Email_Customer_Subscription_Note->handle_multipart, PostsmtpMailer->phpmailer_smtp_init
Postman: 2.0.12
Postman Sender Domain (Envelope|Message): mysite.com | mysite.com
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: SMTP (smtps:login://smtp.hostinger.com.br:587)
Postman Active Transport Status (Ready|Connected): Yes | Yes
Postman Deliveries (Success|Fail): 0 | 0

What could be wrong?