Reply To: Mobile form submission very slow

This is the Post SMTP – Diagnostic test, I hope these are useful they don’t mean much to me.:

Mailer: postsmtp
HostName: enterprise-storage.com.au
cURL Version: 7.65.0
OpenSSL Version: OpenSSL/1.0.2r
OS: Linux web9.hosting-servers.com.au 3.10.0-962.3.2.lve1.5.24.9.el7.x86_64 #1 SMP Wed Feb 13 08:24:50 EST 2019 x86_64
PHP: Linux 7.1.30 C
PHP Dependencies: iconv=Yes, spl_autoload=Yes, openssl=Yes, sockets=Yes, allow_url_fopen=Yes, mcrypt=Yes, zlib_encode=Yes
WordPress: 5.2.2 en_US UTF-8
WordPress Theme: Consulting
WordPress Plugins: All-in-One WP Migration Unlimited Extension, All-in-One WP Migration, Custom Icons by Stylemixthemes, Force Regenerate Thumbnails, Head and Footer Scripts Inserter, Indeed My Testimonials (Visual Composer Version), WPBakery Page Builder, Metronet Tag Manager, Post Duplicator, Post SMTP, Quform, Really Simple SSL, Slider Revolution, Simple Share Buttons Adder, STM Importer, STM Configurations, TinyMCE Advanced, W3 Total Cache, Yoast SEO, WP Admin Menu Manager
WordPress wp_mail Owner: /home/enterprisestorag/public_html/storeme/wp-content/plugins/post-smtp/Postman/PostmanWpMailBinder.php
WordPress wp_mail Filter(s): wp_staticize_emoji_for_email
Postman: 2.0.2
Postman Sender Domain (Envelope|Message): enterprise-storage.com.au | enterprise-storage.com.au
Postman Prevent Message Sender Override (Email|Name): No | No
Postman Active Transport: SMTP (smtp:tls:plain://4446.smtp.antispamcloud.com:587)
Postman Active Transport Status (Ready|Connected): Yes | Yes
Postman Deliveries (Success|Fail): 118 | 2