Hi @tneville,
Thanks for your quick response.
Here is the diagnostic log.
Mailer: postsmtp
HostName: example.com
cURL Version: 7.45.0
OpenSSL Version: OpenSSL/1.0.1e
OS: Linux n2n2wpweb003.prod.aws3.secureserver.net 4.4.216-1.el6.elrepo.x86_64 #1 SMP Wed Mar 11 09:29:51 EDT 2020 x86_64
PHP: Linux 7.3.12 C
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=Yes, allow_url_fopen=Yes, mcrypt=Yes, zlib_encode=Yes
WordPress: 5.6 en_US UTF-8
WordPress Theme: trixxmanaty
WordPress Plugins: Ecommerce Order Tracking and Shipment Notifications - AfterShip, Auto Image Alt, iThemes Security, Classic Editor, Code Snippets, Contact Form 7, Facebook for WooCommerce, Flexible Shipping, Google Analytics for WordPress by MonsterInsights, reCaptcha by BestWebSoft, HTML Page Sitemap, Imagify, Jetpack by WordPress.com, Salient WPBakery Page Builder, Kadence WooCommerce Email Designer, Mailchimp for WooCommerce, NotificationX, Facebook for WordPress, WooCommerce PayZone Secure Payments (redirect), Post SMTP, Self-Hosted Google Fonts, UpdraftPlus - Backup/Restore, Upsell Order Bump Offer for WooCommerce, Advanced Order Export For WooCommerce, Abandoned Cart Lite for WooCommerce, WooCommerce Export Customer Email, WooCommerce PDF Invoices & Packing Slips, WooCommerce, Yoast SEO, WP Mail Logging, WP Rocket, Markup (JSON-LD) structured in schema.org, WhatsApp Click to Chat
WordPress wp_mail Owner: /var/www/wp-content/plugins/post-smtp/Postman/PostmanWpMailBinder.php
WordPress wp_mail Filter(s): wp_staticize_emoji_for_email, WPO\WC\PDF_Invoices\Main->set_phpmailer_validator, PostsmtpMailer->get_mail_args, No3x\WPML\WPML_Plugin->log_email
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
Postman: 2.0.20
Postman Sender Domain (Envelope|Message): example.com | example.com
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: Gmail API (https:oauth2://www.googleapis.com:443)
Postman Active Transport Status (Ready|Connected): Yes | Yes
Postman Deliveries (Success|Fail): 9496 | 539
It seems to work if I disable the Facebook for WordPress plugin.
Thanks