Incorrect authentication data

I have this error:
Incorrect authentication data

Test:
Mailer: postsmtp
HostName: libreriallerapacios.com
cURL Version: 7.71.0
OpenSSL Version: OpenSSL/1.1.1g
OS: Linux dafne.dns-es.com 3.10.0-962.3.2.lve1.5.38.el7.x86_64 #1 SMP Thu Jun 18 05:28:41 EDT 2020 x86_64
PHP: Linux 7.2.32 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 es_ES UTF-8
WordPress Theme: Flatsome Child
WordPress Plugins: Ad Inserter Pro, Classic Editor, Code Snippets, FormCraft, Info Box, Jetpack by WordPress.com, LiteSpeed Cache, Mailster – Email Newsletter Plugin for WordPress, PixelYourSite PRO, Post SMTP, Product Filter for WooCommerce, Product Catalog Feed Pro by PixelYourSite, RDFa Breadcrumb, Redirection, Shortcodes Ultimate, WC Cancel Order, WooCommerce Dynamic Pricing & Discounts, WooCommerce Cart Abandonment Recovery, WooCommerce Blocks, Woo Search Box, WooCommerce Extended Coupon Features FREE, WooCommerce Stripe Gateway, WooCommerce Mailster, WooCommerce Perfect SEO Url, WooCommerce Table Rate Shipping, WooCommerce, WooSidebars, Yoast SEO Premium, Shield Security, Connectif for WordPress, Yoast SEO: WooCommerce
WordPress wp_mail Owner: /home/libreria/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): PostsmtpMailer->phpmailer_smtp_init
Postman: 2.0.12
Postman Sender Domain (Envelope|Message): libreriallerapacios.com | libreriallerapacios.com
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: SMTP (smtp:none:plain://relay-hosting.secureserver.net:587)
Postman Active Transport Status (Ready|Connected): Yes | Yes
Postman Deliveries (Success|Fail): 65844 | 2455